I'm not criminalizing using a wireless connector.. I realize that often times, the router/modem is too far away to stretch a cord. My point about it was that in my house, I never had to deal with connecting wirelessly. At my Dad's, he uses a wireless connector. I prefer to connect to the modem directly, because from what I have heard, it is the best way to go.
If you have your xbox downstairs, and the only way to play would be to play wirelessly.. More power to you. This thread didn't have anything that was specifically saying to play a certain way.. But rather individual experiences on OPEN NAT types compared to MODERATE NAT types.