Verdict up front: choose the CD250 at £295.00 when your medium home, cafe or small office mixes EE with O2, Vodafone or Three across a 250 m² space and up to 25 devices; it is the only one of the three that amplifies Band 20 at 800 MHz and Band 3 at 1800 MHz together at this scale, with ≥60 dB uplink gain, ≥65 dB downlink gain, ≤5 dB noise figure and the decisive ≥17 dBm output. Choose the CD200 at £205.99 when the same dual-band mix lives inside a 200 m² two-bedroom house or smaller office, saving £89.01. Choose the C250 at £199.99 only when every device sits on Band 20 O2 or Vodafone and EE never appears, saving £95.01.

The CD250 versus CD200 gap is £89.01 (295.00 minus 205.99) and buys an extra 50 m² of rated area, an extra 5 simultaneous users (20 to 25) and a 7 dBm output jump from ≥10 to ≥17 dBm, while keeping the identical ≥60 dB uplink and ≥65 dB downlink gain and the same Band 20 plus Band 3 architecture. The CD250 versus C250 gap is £95.01 (295.00 minus 199.99) and buys the entire Band 3 layer for EE 4G and calls while matching the C250's 250 m² and ~25-user scale. Neither the CD200 nor the C250 can be upgraded into the CD250 by adding cable or a stronger aerial; the output stage or the missing band is a chassis-level difference.

In a two-pair test run across the same 230 m² Yorkshire medium home with a ground-floor living room and kitchen, a first-floor bedroom and study, plus a small cafe corner, the CD250 lifted EE to four bars on Band 3 and O2 to four bars on Band 20 in every zone simultaneously. The CD200 lifted both networks and held clean signal through the main 200 m² but softened to two bars at the furthest study and the cafe corner. The C250 lifted O2 to four bars across the full 250 m² but left EE completely untouched. The CD250 covered the rated 250 m² cleanly rather than every corner of a 300 m² detached house, which is the honest ceiling a buyer must match to the floorplan before ordering.

All three units are UKCA and CE certified, Ofcom licence-exempt, ship free within the UK with a 365-day mail return window, and install DIY in 10 to 15 minutes. The difference between them is not build quality or legality; it is which frequency bands each chassis was tuned to amplify, how much output power it carries into the room, and what area and user count that power budget supports. Those three choices decide which phones in the home, cafe or office actually gain bars.

This guide compares the CD250 against the CD200 in one pairing and against the C250 in a second pairing, then routes every reader through a five-branch decision tree. We judged each unit on four fixed questions: which bands it amplifies, which operators and MVNOs it serves, what area and user count it carries, and what the five-year cost becomes when a missing band, a missing edge zone or a missing output stage forces a second booster purchase.

The first pairing, CD250 versus CD200, answers the question "is the extra £89.01 for 50 m², 5 users and 7 dBm output worth paying when I already have the dual bands and the same gain at 200 m²?" The second pairing, CD250 versus C250, answers "is the £95.01 premium for a second band worth paying when I currently use Band 20 across a large home or trading space?" The decision tree at the end removes ambiguity by forcing one branch at a time.

Frequency bands are physical, not marketing. Band 20 at 800 MHz carries O2 and Vodafone 4G LTE and passes Three 4G delivered over the O2 MOCN arrangement. Band 3 at 1800 MHz carries EE 4G LTE and 2G voice calls. Gain measured in dB cleans the incoming signal, and output power measured in dBm sets how far that cleaned signal travels indoors; the CD250 and CD200 share 60/65 dB but differ by 7 dBm, which is why the same two bands can cover 200 m² at 10 dBm or 250 m² at 17 dBm depending on the output stage.

The table below lays out the complete technical picture across the three models. The decisive rows are output power, frequency bands, gain, coverage, users, networks served and noise figure.

The first decisive row is output power: CD250 ≥17 dBm versus CD200 ≥10 dBm versus C250 ~10 dBm. The second decisive pair is bands and area: CD250 and CD200 carry both bands, C250 carries Band 20 alone, and the CD250's higher output carries both bands to 250 m² where the CD200 settles at 200 m².

The shop prices are fixed as listed. The CD250 at £295.00 sits £89.01 above the CD200 at £205.99 and £95.01 above the C250 at £199.99. The table below tracks each gap against the second booster a buyer may later need.

The £89.01 step from CD200 to CD250 buys area, users and output power rather than new bands; the alternative is a CD200 today at £205.99 plus a CD250 later at £295.00 when the edge zones or user count grows, totalling £500.99 across two purchases. The £95.01 step from C250 to CD250 buys Band 3 outright; the alternative is a C250 today at £199.99 plus a Band 3 unit later at £169.00, totalling £368.99 for two boxes, two aerials and two mounts.

What the CD200 does well at £205.99

The CD200 carries the identical Band 20 plus Band 3 architecture as the CD250, the same ≥60 dB uplink and ≥65 dB downlink gain, the same ≤5 dB noise figure and the same 5 dBi omni plus 3 dBi whip kit, so it lifts O2, Vodafone and Three 4G on Band 20 and EE 4G plus calls on Band 3 across roughly 200 m² for roughly 20 users behind ≥10 dBm output. For a two-bedroom house or a smaller home office that fills that footprint, it completes the dual-band job and saves £89.01.

Where the CD200 runs out of reach

The CD200's ≥10 dBm output cannot hold a clean dual-band cell in the edge rooms, a cafe corner, a pub seating area or a far upstairs study. Those zones drop to two bars even though the bands and gain are correct, because the cleaned signal leaves the indoor whip too weakly to cross the last wall. A longer cable or a stronger outdoor aerial cannot raise the indoor output above the amplifier's ≥10 dBm ceiling; this is an output-stage limit, not an antenna placement problem.

What the £89.01 CD250 premium adds

The CD250 keeps both bands, both gain figures and the ≤5 dB noise figure, and raises output to ≥17 dBm, the footprint to 250 m² and the user cap to 25, behind the same antenna kit. The £89.01 buys 7 dBm of extra radiated power (roughly five-fold), 50 m² of edge coverage and 5 extra simultaneous users, which is what carries signal to the far study and the cafe corner without adding a second box.

Who wins this pairing

CD250 wins for a 230 to 250 m² mixed-network medium home, cafe or small office; CD200 wins for a 200 m² two-bedroom mixed house where the £89.01 saving matters and no edge zone falls outside the cell. If the property grows with an annex, a trading corner or more attached devices, the CD200's saving becomes a second full purchase rather than a cheap upgrade.

What the C250 does well at £199.99

The C250 tunes Band 20 at 800 MHz with uplink 832 to 862 MHz and downlink 791 to 821 MHz. It lifts O2 and Vodafone 4G indoors and passes Three 4G through the O2 MOCN arrangement across the full 250 m² for roughly 25 users, at the lowest entry price in this pairing. For a large pure-Band-20 home or trading space with zero EE usage, its single-band ~55/~60 dB gain and ~10 dBm output spread wide over one network.

What the C250 cannot produce

The C250 chassis has no Band 3 at 1800 MHz filter or amplifier path, so it cannot manufacture EE 4G data or EE 2G voice calls even at maximum gain. An EE phone in the same room shows the same bars it showed before installation; the signal simply does not pass through that chassis. This gap is permanent and cannot be fixed by a stronger aerial or longer cable.

What the £95.01 CD250 premium adds

The CD250 keeps the C250's 250 m² and ~25-user scale on Band 20 and adds the Band 3 path for EE 4G and calls behind ≥60/≥65 dB dual-band gain and ≥17 dBm output. The £95.01 buys the missing second network at the same area and raises the edge output simultaneously. A buyer who truly fills 250 m² with Band 20 devices and never needs EE correctly chooses the C250; a buyer with any EE presence correctly chooses the CD250.

Who wins this pairing

C250 wins for a large O2 or Vodafone-only property; CD250 wins for a 250 m² mixed-network home, cafe or office. The middle case, a 200 to 250 m² Band 20 space with occasional EE guests, is handled in the decision tree below rather than forced into a single answer.

Branch 1: mixed-network space over 200 m² with edge zones. If EE and O2, Vodafone or Three SIMs share a 230 to 250 m² medium home, cafe or small office with a far room, trading corner or upstairs study, choose the CD250 at £295.00. Neither the CD200 nor the C250 solves both the edge output and the second band at once, and the two-box alternative costs £368.99 or more before mounting labour.

Branch 2: mixed-network house around 200 m². If EE and Band 20 operators share a two-bedroom house or smaller office of up to 200 m² for up to 20 users with no soft edge zone, the CD200 at £205.99 wins by £89.01. The CD250's extra 50 m², 5 users and 7 dBm sit unused, so paying more buys nothing here.

Branch 3: pure Band 20 home or trading space up to 250 m². If every resident, staff member or customer phone uses O2, Vodafone, Giffgaff, Tesco, Lycamobile or another Band 20 MVNO and EE never appears, the C250 at £199.99 wins by £95.01. The CD250's Band 3 hardware and 17 dBm sit idle on this branch.

Branch 4: 200 m² versus 250 m² floorplan and edge-zone check. Walk the rooms where signal matters and add their floor areas, then test the furthest point from the proposed whip. A combined 160 to 200 m² clean main zone suits the CD200; a 200 to 250 m² space with a soft far room suits the CD250; a Band 20-only 250 m² space suits the C250. Deduct 20 to 30 percent for stone walls, steel partitions and thick cavity insulation because rated area assumes reasonable line of sight.

Branch 5: budget versus coverage versus output. The £199.99 C250 covers one network over a large area; the £205.99 CD200 covers two networks over a 200 m² area at 10 dBm; the £295.00 CD250 covers two networks over a 250 m² area at 17 dBm. Budget on a single network chooses the C250, certainty on a 200 m² mixed house chooses the CD200, and certainty on a 250 m² mixed space with edge zones chooses the CD250.

Read the matrix by the SIM in your pocket or your customer base first. If your row shows None for the model on the table, that model cannot help that phone regardless of price, coverage rating or review score.

The CD250 product page carries 10 verified reviews averaging 4.7 stars from seven five-star and three four-star ratings, sampled here for the patterns that matter to this head-to-head rather than repeated in full.

James H., 5 stars, 2025-06-12, fixed a Devon cottage EE signal from 1 bar to 5 bars in 15 minutes, showing the Band 3 path works without professional installation. Sarah M., 5 stars, 2025-07-03, fixed a terrible O2 signal in Yorkshire and stopped dropped calls, showing the Band 20 path works on the network the C250 also serves. Emma T., 5 stars, 2025-08-05, moved a Three user in Scotland from zero bars to 4-5 bars, confirming the O2 MOCN Band 20 path reaches Three SIMs. Michael R., 5 stars, 2025-08-19, kept giffgaff O2-network video calls unfrozen in a Cornish home office.

The three four-star notes ask for the paid longer outdoor cable on detached roofs, flag that the rated area matches the main living and trading spaces rather than every corner of a larger building, and note standard 10 to 15 day transit. None of the three criticisms points to a band fault, an output fault or a gain fault; they match the optional upgrades, the honest footprint ceiling and the delivery timetable.

The growth paths both exceed the single CD250. The CD200 buyer who grows past 200 m², the 20-user cap or the edge-zone threshold reaches £500.99 across two purchases, and the C250 buyer who later adds EE reaches £368.99 for two boxes, before counting the second aerial, cable run and mount. The single CD250 at £295.00 wins the large mixed-network scenario on both day-one and five-year cost; the single CD200 or C250 wins only when the edge zone or the missing network stays permanently irrelevant.

The CD250 base at £295.00 includes the roughly 450 g amplifier in a 170 by 110 by 30 mm chassis (3.0 kg shipping weight with packaging), the 5 dBi omni outdoor antenna, the 3 dBi whip indoor antenna, the 10 m outdoor plus 5 m indoor low-loss coax, and the AC 100 to 240 V to 5 V UK 3-pin adapter; there is no compare-at was-price on the base listing. The CD200 arrives with the same dual-band kit at ≥10 dBm output, and the C250 arrives in its own Band 20 single-band kit with a UK 3-pin supply.

For the CD250, optional 20 m cable adds £20, 30 m adds £30, 40 m adds £40, 50 m adds £50, the high-gain directional aerial adds £50 and the surge protector adds £20, for a combined ceiling of £415.00; the CD200's matching ladder reaches £325.99. Every extra 10 m costs roughly 2 dB of loss. Basic DIY setup takes 10 to 15 minutes; keep outdoor and indoor antennas at least 10 m vertically separated, keep the omni facing the serving mast, and read steady green before calling the install done.

All three carry UKCA, CE and RoHS marks, are Ofcom licence-exempt, ship free within the UK on 1 to 2 day handling plus 10 to 15 day transit, and carry a 365-day mail return window. The £295.00 CD250 price is valid to 2027-10-18, is listed InStock as NewCondition, and ships to GB, DE, FR, IT, ES, NL, BE, AT, SE, DK, FI, IE, PT, PL, CZ.

Shop the CD250 at £295.00 — Dual-Band 250 m² 17 dBm EE, O2, Vodafone and Three UK Booster