Answer up front: if your household, detached home, cafe, medium office or small hotel runs O2 or Vodafone SIMs and needs 4G data plus boosted 2G voice calls across a 500m² footprint for up to 50 simultaneous users, the CG500 at £485.00 is the pick; it pairs Band 20 at 800 MHz data with Band 8 at 900 MHz calls, holds ≥60 dB uplink and ≥65 dB downlink gain, outputs ≥20 dBm (roughly twice the CG250's ≥17 dBm over +3 dB), feeds up to 3 indoor antennas, includes the high-gain Yagi in the full kit, and ships the 10m outdoor plus 5m indoor cable pair. If you only need a 250m² three-bedroom home for 25 users and can save £190.00, the CG250 at £295.00 carries the same Band 20+8 stack at ≥17 dBm with the Yagi sold separately. If your SIMs are EE-led and you want EE data plus EE calls rather than O2/Vodafone voice, the CD500 at £485.00 swaps Band 8 for Band 3 at the same output, size and included Yagi.

The £190.00 CG500-vs-CG250 gap (485.00 minus 295.00) buys +250m² (doubling the footprint), +25 users (doubling the count), +3 dB output power (≥20 vs ≥17 dBm, ≈2x), and the included Yagi, while gain stays ≥60/≥65 dB and the bands stay Band 20+8. The £0.00 CG500-vs-CD500 gap buys different operators rather than more machine: same 500m², same 50 users, same ≥20 dBm, same gain, same Yagi, but the CD500's Band 3 at 1800 MHz serves EE voice while the CG500's Band 8 at 900 MHz serves O2/Vodafone voice. No single unit boosts EE calls and O2/Vodafone calls together, because those two call layers live on different bands this chassis family does not combine.

This page compares the three Boost4U chassis side by side rather than in a roundup: the CG500, the CG250 and the CD500. It separates the data layer on Band 20 (shared by all three) from the voice layer (Band 8 on the two CG units, Band 3 on the CD unit), sizes the output-power and footprint difference between CG500 and CG250, and gives a five-branch decision tree so the choice follows which SIMs you hold, how big the zone is, how many devices attach, whether the Yagi matters, and whether budget or coverage decides.

All three 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. None carries 3G Band 1 at 2100 MHz or 5G; all run from an AC 100–240V to DC 5V UK 3-pin adapter. The rest of this page numbers every gap in pounds, dBm, square metres, users and antennas before you order.

Before the tables, three rules keep the comparison honest. First, Band 20 at 800 MHz (uplink 832–862 MHz, downlink 791–821 MHz) is shared by all three and carries O2, Vodafone and Three 4G data, so data capability is not the deciding factor; the deciding factor is which voice band the chassis amplifies. Second, the CG500 and CG250 share Band 8 at 900 MHz (uplink 890–915 MHz, downlink 935–960 MHz) for O2/Vodafone 2G calls and SMS; the CD500 instead tunes Band 3 at 1800 MHz for EE 2G calls. Third, between the two CG units, gain is identical (≥60/≥65 dB) and only output power, area, users, antenna count and included Yagi differ, so the CG250 question is purely "do I need 500m², 50 users, ≥20 dBm and the included Yagi today or later?"

Output power matters more than sticker price for a wide footprint. The CG500's ≥20 dBm drives the cleaned signal across 500m² and up to 3 whips, while the CG250's ≥17 dBm holds a 250m² cell; the +3 dB gap is roughly twice the transmit power, not a louder tone but a reachable signal to more antennas and rooms. Gain cleans the donor identically on both CG units, so raising output rather than gain is the engineering choice for doubled spread, and the included Yagi replaces the CG250's paid aerial upgrade.

Coverage figures assume reasonable donor signal outside and 10m vertical separation between the outdoor omni/Yagi and indoor whip; a weak rural donor at −97 to −105 dBm uses the CG500's included Yagi aimed at the nearest mast, while the CG250 buyer adds the +£50 Yagi separately; a strong donor at −70 to −90 dBm lets both units add a second and third indoor antenna via splitter and extra cable, up to 3 total. The tables below compare specs, price gaps and day-one versus five-year cost before the decision tree.

Read the voice rows before the price rows: both CG units boost O2/Vodafone calls, only CD500 boosts EE calls, and all three boost O2/Vodafone/Three 4G data on the shared Band 20; then read output power and the included Yagi, where CG500 and CD500 share ≥20 dBm and included Yagi, and CG250 sits at ≥17 dBm with a paid Yagi.

The £190.00 CG250 saving buys a smaller footprint, lower output and a paid Yagi, not a different network; the £0.00 CD500 tie changes only the voice operator. Neither gap buys more data speed, because Band 20 data is identical across all three chassis.

The CG500 and CG250 tune the identical two bands: Band 20 at 800 MHz for O2, Vodafone and Three 4G data, and Band 8 at 900 MHz for O2/Vodafone 2G voice calls and SMS, and they share the same ≥60 dB uplink and ≥65 dB downlink gain. If both sit in a single broad room, they look the same because the shared donor, Band 20 data and Band 8 voice work on either chassis. The difference appears as the zone doubles: the CG500 raises output from ≥17 to ≥20 dBm, which spreads the cleaned signal across 500m² for 50 users and feeds up to 3 indoor antennas, where the CG250 holds a 250m² cell for 25 users.

The +£190.00 line item by line item

For £190.00 (485.00 minus 295.00), the CG500 adds: +250m² of rated indoor area (500 versus 250, exactly double); +25 simultaneous users (50 versus 25, exactly double); +3 dB output power (≥20 versus ≥17 dBm, roughly twice the transmit power); and the high-gain Yagi directional aerial included in the full kit rather than the CG250's +£50 paid upgrade. Gain, bands, noise figure ≤5 dB, 3 dBi whip family, up to 3 antennas, and the 10m outdoor plus 5m indoor cable stack are matched.

Where the CG250 still wins

The CG250 at £295.00 wins on entry price by £190.00 and is the honest choice for a three-bedroom home, a small cafe, or a home where the boosted signal reaches 250m² and active devices stay at 25 or fewer. In that footprint the doubled 500m², 50 users, ≥20 dBm and included Yagi are unused capacity, and the lower price plus the same Band 20+8 data-and-calls path makes the CG250 the value pick.

Where the CG500 becomes unavoidable

Once the layout is a detached house, a large hotel floor, a medium office or a cafe spanning counter, seating and back rooms, the CG250's ≥17 dBm, 250m² and 25-user rating thins beyond the second broad zone. The CG500's ≥20 dBm and 50-user headroom keep data and calls connected across the full footprint, the included Yagi handles a weak rural donor without a separate aerial purchase, and the third indoor antenna on a splitter covers a separate zone without buying a new box. Buying CG250 now and CG500 later costs 295.00 plus 485.00 rather than choosing the CG500 once for a 500m² layout.

The CG500 and CD500 are a £0.00 tie on upfront price, area (500m²), users (50), gain (≥60/≥65 dB), output power (≥20 dBm), antenna count (3) and the included Yagi; even the 10m outdoor plus 5m indoor cable stack matches. The whole difference is the voice band the chassis amplifies, because both share Band 20 for O2/Vodafone/Three 4G data.

CG500 Band 8: O2 and Vodafone calls

The CG500 tunes Band 8 at 900 MHz (uplink 890–915 MHz, downlink 935–960 MHz). On O2 and Vodafone SIMs this boosts 2G voice calls and SMS indoors, and 900 MHz also reaches deeper through masonry than higher bands. MVNOs on the O2 network (giffgaff, Sky Mobile, Talkmobile, Lycamobile, Tesco) and on Vodafone (Lebara 2G, TalkTalk 2G) ride this same call layer. EE receives Band 20 4G data only; the CG500 does not tune EE's Band 3 voice.

CD500 Band 3: EE data and calls

The CD500 tunes Band 3 at 1800 MHz instead, which carries EE 4G data and EE 2G voice. An EE-led home or venue gets boosted EE calls that the CG500 cannot provide; in return, O2 and Vodafone SIMs receive Band 20 data only, with the call channel left native on 2G rather than boosted. The CD500 cannot add Band 8 later, and the CG500 cannot add Band 3 later; these are fixed voice layers, not switchable modules.

The £0.00 tie decides by SIM, not by spec

Because price, area, users, gain, output, antennas and the Yagi are identical, the CG500-versus-CD500 choice is a pure operator question: O2/Vodafone-led household or venue with calls = CG500; EE-led venue with calls = CD500; mixed where EE voice and O2/Vodafone voice both matter = no single chassis solves both, and a second band-specific unit or a larger multi-band system is required rather than forcing one box.

Walk the branches top to bottom and stop at the first yes.

Branch 1 — Are your main SIMs O2 or Vodafone (incl. giffgaff, Sky, Talkmobile, Lycamobile, Tesco, Lebara, TalkTalk) and do calls drop indoors?

Yes on both: the Band 8 call layer matters, so stay inside the CG family. Move to Branch 2 for size and output; do not pick the CD500, which leaves these calls native.

Branch 2 — Is the footprint 250m² or smaller (three-bedroom home, two-three rooms), active devices 25 or fewer, and budget the deciding factor?

Yes: CG250 at £295.00, Band 20+8, ≥17dBm, Yagi paid separately, save £190.00. No (detached house, hotel floor, medium office, 26–50 active devices, four-plus rooms, or weak rural donor needing the included Yagi): CG500 at £485.00, 500m², 50 users, ≥20dBm, Yagi included.

Branch 3 — Are the main SIMs EE-led and does EE voice drop indoors while O2/Vodafone appear only as data?

Yes: CD500 at £485.00, Band 20+3, EE data and calls across 500m² for 50 users at ≥20dBm with Yagi included. Do not reach for the CG500 because it never boosts EE Band 3 voice.

Branch 4 — Do you need both EE boosted calls AND O2/Vodafone boosted calls in one home or venue?

Yes: none of the three chassis covers both voice layers; plan a band-specific second unit or a larger multi-band system rather than overloading a single box. No: return to Branch 1 or 3.

Branch 5 — Is the site a multi-storey commercial block, a linked annex, 3G Band 1, or 5G?

Yes: a single 500m² chassis is undersized or band-wrong; choose a larger or multi-band commercial system. No and the zone fits 500m²: return to Branch 1, 2 or 3 and order the matched unit.

Day one, CG500 and CD500 tie at £485.00 and CG250 sits at £295.00. The five-year total separates them when a second purchase appears.

The CG250 buyer who expands later pays 295.00 plus a 500m² chassis before the second aerial, splitter, cable run and install; the CD500 buyer who later adds an O2/Vodafone call layer pays a Band 8 unit on top of the 485.00 already spent. Only the correctly matched single CG500 or CD500 closes the job day one at £485.00. The £190.00 CG250 saving evaporates when growth forces the second box.

The CG500 box at £485.00 holds the ~450 g amplifier (170×110×30 mm, 3.0 kg shipping), the 5 dBi omni outdoor aerial, the included high-gain Yagi, the 3 dBi whip indoor antenna, the 10m outdoor low-loss coax, the separate 5m indoor coax, and the AC 100–240V 50/60Hz to DC 5V UK 3-pin adapter; there is no paid external-aerial variant because the Yagi already comes in the full kit. Optional: 20m (+£20), 30m (+£30), 40m (+£40), 50m (+£50) cable; protector (+£20); max optional combo £555.00. The CG250 box carries the same cable stack at ≥17dBm with the Yagi +£50; the CD500 box matches the CG500 cable stack and included Yagi for its EE job.

Basic setup takes 10 to 15 minutes without tools: fix the omni or the aimed Yagi outside with a clear mast view, keep the indoor whip at least 10 m vertical below, run the outdoor and indoor coax, power from the UK 3-pin adapter, and read steady green before testing. Strong donor at −70 to −90 dBm permits up to 3 indoor antennas via a 2-way or 3-way splitter and extra cable; weak donor at −97 to −105 dBm uses the included Yagi aimed at the mast before any cable upgrade. The custom note reads "Expandable coverage by adding indoor antenna, splitter, cable if the outside signal is strong."

All three carry UKCA, CE and RoHS, are Ofcom licence-exempt, ship free within the UK (handling 1–2 days, transit 10–15 days), and carry a 365-day mail return window. The £485.00 CG500 price is valid to 2027-10-18, InStock NewCondition, and ships to GB, DE, FR, IT, ES, NL, BE, AT, SE, DK, FI, IE, PT, PL and CZ; the CG250 at £295.00 and CD500 at £485.00 follow the same shipping and return terms.

O2/Vodafone detached home or venue, 500m², 50 devices, calls must hold, weak donor needs the Yagi: CG500 at £485.00, Band 20+8, ≥20dBm, Yagi included, the only high-output 500m² box that boosts O2/Vodafone calls.

O2/Vodafone home, up to 250m², 25 devices, save £190.00: CG250 at £295.00, same bands, lower output, Yagi paid separately, smaller footprint.

EE-led venue, 500m², EE calls matter: CD500 at £485.00, Band 20+3, accept O2/Vodafone data-only.

Quick verdict: pay the £190.00 for CG500 only when the zone reaches 500m², 50 users, ≥20dBm and an included Yagi; at the £0.00 tie, CG500 serves O2/Vodafone calls and CD500 serves EE calls, so match the voice band to your SIM and the output to the footprint rather than chasing the biggest spec sheet.