I have wireless that I use when a friend or my girlfriend uses the Ethernet. It's not much of a difference for me, lag every now and then but not that big of a deal. But of course, wired is always better
I have a cable modem and wireless router. I have a line running to my living room. I might as well put two ends on it and hardwire the xbox. You guys are right, if I get 3ms better response time, it's still better.