Only peripherally related to this discussion, but...

My internet comes to me on a 15Mbit/sec cable modem and a WRT54G2 router. My computer and SWMBO's computer are wired directly to the router with Ethernet. My downstairs neighbor (and the one below her) are using the wireless signal from the router. (It's a bit more complex than that: they receive their signal from a second WRT54G that is being used as a repeater from my WRT54G2 because there is so much steel in my house that my signal can't propagate directly to them.)

I have run speed tests and I do receive consistent 14-15 Mbit/sec downloads at my directly-wired computer. Can my downstairs neighbors expect to receive comparable speeds after going through the two wireless routers?

tanstaafl.