Has anyone tried using port triggering versus port forwarding? Reason I ask is that for homes with multiple Xboxes or PS3s, this setup would not work due to port forwarding working for a single IP address/device. For some reason, when I play MW2, I'll do lights-out when I'm not the host, when I am the host, it's lag-city. I'd expect that the RoadRunner Turbo package (25 down/2 up) would be enough to run two Xboxes in a party.
Edit: Both consoles are hard-wired using Cat 6.