I know what you mean, man. I have been battling lag on Halo 2 since I got here, and it’s really ruined the game for me. I came back a little early after winter break when few people were here, and the lag was substantially less, but as soon as people started returning, the lag did too. I think the network here really just can’t handle gaming.
It isn’t just Xbox either. Connect to BF2 and check your ping- it might just be me but I’ve seen it be over 1000. You don’t notice the lag as much on GOW because the game is a little more forgiving then Halo 2, but if you suspect lag, aim a shotgun at the ground and watch how long it takes for the shot to hit. 1-2 seconds is not normal haha.
Also, different residences seem to be better or worse. I lived in Lwood earlier this year and XBL almost made me pull out my hair or Gears OR on Halo. I’m in Norton now, and while Gears is a lot more enjoyable, I still shy away from Halo as it is often still pretty laggy. Ping will be green, then you get killed, yell lag, and then see it in the yellow or red where it stays for a while, only to return to green, giving you false hope. Repeat.
In summary: don’t bother with XBL unless… well unless you like lag.