Does this mean that I could connect a BT Infinity router in the same
> location as my existing router and have a reasonable expectation of it
> working? (Locating the router in the hallway and re-wiring the house
> with Cat5 data cable is simply not going to happen).
It really depends on just how the internal wiring is performing. It could, for example, pick up interference from nearby other cables, etc. All you can do is try it and see. I'm using my BT infinity Wi-Fi connection to a TV, and that works fine. Cabled is probably faster on paper - but in practice few things can take advantage of this max speed anyway. Although I do have CAT5e to this computer - which can't do Wi-Fi anyway.