OK. Cool. If it's a 802.11n router, then that sounds about reasonable for real life figures - somewhere around double what you'd get for 802.11g.

OK I see you wanted bridging initially. I assumed the WDS you ended up with was what you were trying for. It's unlikely the Airport would support bridging I would think. Very few routers do that I've seen - the Linksys WRT54G routers only do it with the 3rd part firmware, not with the factory firmware.

Like many things Apple, I'd expect the amount of configuration options to be somewhat limited and bridging would be one of the first to not be there...