First, the bad stuff. I don't understand how you can have a > 100 Mbps router and have it not be able to handle even a dozen simultaneous sessions. This just goes to show that having a fast router doesn't mean that it will automatically handle P2P applications well.
From my background with Belkin, there routers never performed well in a p2p environment. I had the old wireless G and the new G router. Both have serious issues with p2p2 connections.
The F5D7230 stops responding when a p2p app. is started and the older model choked resulting in slow speed and often cutting all other traffic.
My guess would be Belkin is not in the market for p2p routers.
Belkin wireless kit is pretty poor in general anyway. A neighbour bought a -g router. The range was literally a few feet. The corresponding PCMCIA adaptor was extremely fragile - poor to begin with, then when dropped from (not very high) completely useless.
An indication of how bad it was is that they bought a Linksys WRTG54 V5 router, and that is much better! The Linksys-at-home PCMCIA adaptor from Tesco has stood up to quite a bit of teenage usage.