Verdict up front: for an O2 or Vodafone home needing 4G data plus boosted 2G voice calls in a 100m² room, small flat or home office, the CG100 at £185.99 wins this head-to-head. It keeps Band 20 data for O2, Vodafone and Three and adds the Band 8 at 900 MHz call layer for O2/Vodafone voice behind ≥45/≥50 dB gain, ≥10 dBm output and a ≤5 dB noise figure, for 10 simultaneous users on a UK plug. The CD100 at £185.99 wins only for an EE-dominant household needing EE data and EE calls; the C100 at £109.99 wins only for a pure data-only Band 20 budget where calls never matter.

The CG100 versus CD100 gap is £0.00: both cost £185.99, but the CD100 tunes Band 20+3 for EE data-and-voice and has no Band 8, so O2/Vodafone calls stay native. The CG100 versus C100 gap is £76.00 (185.99 minus 109.99) and buys the Band 8 call layer plus the dual-band chassis, where the C100 carries Band 20 data alone.

In a Yorkshire O2 home and a Welsh Vodafone office, the CG100 held four bars of data and kept calls connected without dropping; the CD100 would have lifted EE data and calls but left those O2/Vodafone calls native, while the C100 would have lifted data alone with no boosted voice. The deciding factor is the operator's call layer, not raw data bars, because all three share the Band 20 data path for O2, Vodafone and Three.

This head-to-head compares only the three Boost4U catalogue units, so no US import estimate appears in the buying decision; the roundup blog covers the no-name marketplace unit and the weBoost Home around £350 estimated as benchmarks. All three units here are UKCA and CE certified, 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.

We judge the CG100, CD100 and C100 on five fixed questions rather than brand names: which frequency bands each chassis tunes, which operators receive 4G data versus data-plus-voice, what 100m² indoor area and user count it supports, how it mounts and powers in a UK home, and what the five-year cost becomes once a missing voice or data layer forces a second purchase. The sections below pair CG100 against CD100, then CG100 against C100, before the five-branch decision tree.

Frequency bands decide networks before price, and this matters most where CG100 and CD100 share a price tag. Band 20 at 800 MHz (uplink 832 to 862 MHz, downlink 791 to 821 MHz) carries O2, Vodafone and Three 4G LTE data, with Three attaching through the O2 MOCN arrangement. Band 8 at 900 MHz (uplink 890 to 915 MHz, downlink 935 to 960 MHz) carries O2 and Vodafone 2G voice and SMS indoors. Band 3 at 1800 MHz carries EE 4G data and EE 2G voice. A chassis tuned to one band cannot manufacture the others, no matter how many bars it shows on data.

Gain measured in dB cleans the weak donor signal; output power measured in dBm sets the radiated ceiling inside the room. The CG100 holds ≥45 dB uplink and ≥50 dB downlink at ≥10 dBm behind a ≤5 dB noise figure; the CD100 and C100 sit in class-rated envelopes on their own band sets. The 45/50 dB pair is sized for a single room or small flat rather than a whole house.

Indoor coverage assumes reasonable donor signal outside and 10 m vertical separation between omni and whip; the rated 100m² covers living room plus kitchen, a studio flat or one home office. User capacity counts active phones attaching to one boosted cell before the serving tower scheduler congests, rated at 10 for the CG100 and class-rated for the others. Mounting and power decide whether the unit fits a rented flat, a shop or a detached house without wiring changes.

The decisive rows are frequency bands and who receives a boosted call. CG100 and CD100 share the £185.99 price and Band 20 data but differ on Band 8 versus Band 3 voice; C100 shares Band 20 with CG100 but omits every voice band at a £76 lower price.

The £0.00 CD100 gap buys EE voice rather than O2/Vodafone voice, not more coverage; the £76.00 C100 saving buys Band 20 data only and leaves calls to a £169.00 second box, reaching £278.99 for two units where a clean single install was possible. The single CG100 at £185.99 covers both data and O2/Vodafone voice day one and wins on both day-one and five-year cost for an O2/Vodafone household.

What the CD100 does well at £185.99

The CD100 tunes Band 20 at 800 MHz for shared O2, Vodafone and Three 4G data plus Band 3 at 1800 MHz for EE 4G data and EE 2G calls. It covers the same 100m² and 10-user class on a UK plug install, lifting EE data and EE voice inside the room. For an EE-dominant household that also wants shared Band 20 data, it completes that narrower job at the same price.

Where the CD100 leaves the O2/Vodafone call layer

The CD100 chassis has no Band 8 at 900 MHz filter or amplifier path, so it cannot manufacture O2 or Vodafone 2G voice even at maximum gain. An O2 or Vodafone phone making a native call inside the house shows the same call quality it showed before installation; the voice layer simply does not pass through that chassis. This gap is permanent and cannot be fixed by a stronger aerial or longer cable. Because the CD100 and CG100 share a price tag, the spec sheet's frequency rows, not the price, decide the purchase.

What the £0.00 CG100 step keeps and adds

The CG100 keeps the CD100's Band 20 data path for O2, Vodafone and Three and adds the Band 8 layer for O2/Vodafone calls at the identical £185.99, behind ≥45/≥50 dB gain, ≥10 dBm output, the 10-user rating and the same UK plug install. The zero-price step buys a different operator's voice layer rather than new features; the EE-only household loses nothing, and the O2/Vodafone-call household gains everything.

Who wins this pairing

CG100 wins for any O2/Vodafone household relying on boosted calls plus shared Band 20 data; CD100 wins only for a single-network EE household needing EE data and EE voice where O2/Vodafone calls never appear. A price comparison alone falsely levels these two, because the voice band underneath differs completely.

What the C100 does well at £109.99

The C100 tunes Band 20 at 800 MHz with uplink 832 to 862 MHz and downlink 791 to 821 MHz. It lifts O2, Vodafone and Three 4G data across the 100m² zone on a UK plug at a low sticker price. For a pure data-only user on a tight budget, its single-band gain and spread cover one network's data in the room.

What the C100 cannot produce

The C100 chassis has no Band 8 and no Band 3 voice path, so it cannot manufacture O2/Vodafone 2G voice or EE voice calls even at maximum gain; every call remains native. The £76.00 saving is real on day one but buys data coverage only, and adding a voice-capable unit later reaches £278.99 for two boxes in a home where cabling and aerial separation are already set.

What the £76.00 CG100 premium adds

The CG100 keeps the C100's Band 20 O2/Vodafone/Three data coverage, adds the Band 8 O2/Vodafone call layer behind ≥45/≥50 dB gain and ≥10 dBm output, and keeps the same 100m² and 10-user rating. The £76.00 buys the missing call layer at the same data area and user count. A buyer who truly uses data-only and never makes a boosted call correctly considers the C100; any call reliability requirement correctly chooses the CG100.

Who wins this pairing

C100 wins for a pure Band 20 data user on a tight budget where boosted calls never matter; CG100 wins for any O2/Vodafone household that needs data plus connected calls. The middle case, a data-heavy user with occasional dropped calls, is handled in the decision tree below rather than forced into a single answer.

Branch 1: O2/Vodafone home needing 4G data plus boosted calls. If the household phone on O2 or Vodafone drops calls indoors while data works weakly, choose the CG100 at £185.99. Neither the CD100 nor the C100 solves Band 8 voice from one chassis, and the two-box alternative costs £278.99 or more in a room where separation is already set.

Branch 2: EE-dominant home needing EE data and EE calls. If the only active SIM is EE (or an EE MVNO) and you rely on Band 3 4G plus Band 3 voice, the CD100 at £185.99 covers that narrower job, provided O2/Vodafone calls never appear. At the same price the CG100 carries unused Band 8 hardware on this branch.

Branch 3: pure Band 20 data user on a tight budget. If every phone uses O2, Vodafone, giffgaff, Tesco, Lycamobile, Three or another Band 20 SIM and calls never need boosting, the C100 at £109.99 covers Band 20 data and saves £76.00, though it cannot add voice later without a second box.

Branch 4: one-room flat versus home office versus small shop. A rented one-bedroom flat with mixed SIMs suits the CG100; an EE-only commuter flat suits the CD100; a data-only budget room suits the C100. For a small shop with staff and customers, check whether voice calls from O2/Vodafone guests matter before choosing the data-only box.

Branch 5: budget versus network coverage versus calls. The £109.99 C100 covers one network's data at the lowest entry; the £185.99 CD100 covers EE data-and-voice at mid price; the £185.99 CG100 covers O2/Vodafone data-and-voice at the same mid price. Budget on a single data network chooses the C100, certainty on EE calls chooses the CD100, and certainty on O2/Vodafone calls chooses the CG100.

Read the matrix by the SIM in your pocket and whether you need a boosted call. If your row shows No for the model, that model cannot help that phone's call regardless of price.

The CG100 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.

Sarah M., 5 stars, 2025-07-03, fixed a terrible O2 signal in a Yorkshire home and reported calls no longer drop, the clearest Band 8 call-layer result. Michael R., 5 stars, 2025-08-19, ran a giffgaff O2-network home office in Cornwall where video calls no longer freeze. Claire B., 5 stars, 2025-10-01, held consistent 4-5 bars as a Lebara Vodafone user after an easy setup. Rachel S., 5 stars, 2025-11-05, gave a Tesco Mobile customer in a rural village reliable 4G for the first time in three years.

James H., 5 stars, 2025-06-12, installed in a Devon cottage in 15 minutes and reached full 5 bars on EE data; Emma T., 5 stars, 2025-08-05, lifted a Three user in Scotland from zero bars to 4-5; Robert K., 5 stars, 2025-09-15, contrasted a cheap Amazon booster that did nothing against the CG100 working for an EE customer in Norfolk. These data wins arrive on shared Band 20; the CG100 does not add EE voice.

David W., 4 stars, 2025-07-21, needed the long-cable upgrade to reach the roof for a solid Vodafone signal in Wales; Lisa P., 4 stars, 2025-09-02, found living room and kitchen covered but a bigger model needed for the whole house; Andrew G., 4 stars, 2025-10-18, praised solid performance and flagged 12-day delivery as slow. The three four-star notes match the cable upgrade, the honest 100m² ceiling and the delivery timetable; none points to a band fault, a gain fault or a call-layer fault.

The growth paths both exceed the single CG100. The C100 buyer who later adds voice reaches £278.99 for two boxes, before counting the second aerial, cable run and install. The CD100 buyer who later needs O2/Vodafone calls adds a Band 8 unit on top of the same £185.99 already spent. The single CG100 at £185.99 wins the O2/Vodafone data-and-voice scenario on both day-one and five-year cost; the single CD100 or C100 wins only when the missing voice layer stays permanently irrelevant.

The CG100 base at £185.99 includes the roughly 450 g amplifier in a 170 by 110 by 30 mm chassis (3.0 kg shipping weight), the 5 dBi omni outdoor aerial, the 3 dBi whip indoor antenna, the 10 m low-loss coax, and the AC 100–240V to 5V UK 3-pin adapter; there is no compare-at was-price on the base listing. The CD100 arrives in the same home form factor on Band 20+3, and the C100 arrives in its own Band 20 single-band kit with UK plug power.

For the CG100, cable upgrades of 20m (+£20), 30m (+£30), 40m (+£40) and 50m (+£50), an external aerial (+£20) and a protector (+£20) reach the max £305.99 combo, and a second indoor antenna via splitter extends a second zone on strong donor signal. Basic DIY setup takes 10 to 15 minutes; mount the omni with a clear mast view, keep 10 m vertical separation from the whip, route the 10 m coax, 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 £185.99 CG100 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 CG100 at £185.99 — Band 20+8 100m² O2/Vodafone 4G Data and Calls UK Booster