I ran a Belkin 54G router for several years before recently changing to BT, with a Home Hub 2 (a couple of weeks before the HH3 was announced. Grrr!).
I haven't run any comparative home wireless network speed measurements between the two routers, but I can tell you that, with the Belkin, the little wi-fi icon in my computer's (W7) system tray always showed five bars of signal. With the HH2 I normally only get four bars, quite often reducing to three.
There's been no other change to the household equipment layout that might have caused this, and the HH2 occupies exactly the same location that the Belkin did.