Nice thread DS. I play UT for a few months now and haven't yet met the ceiling. When starting to play UT online I wondered if I could ever manage to stay alive for more then 5 seconds with all those godlike players around.
Now I play for a clan which is specialized in DOM and though I'm not a superb player, I can get along with the better players. But again, I don't see the ceiling yet, I'm still improving. But I notice very often that games differ so much. One night you get y'r ass kicked by every bastard you meet and go to sleep with a bad, bad feeling. Hope my wife's asleep otherwise we'lll end up in a fight

Other nights you can "predict" what others are doing and you end up on top of the lists with rampages and dominatings all around.
Can't put my finger on it. Of course, state of mind, amount of sleep, etc. is important, but that's not it. And of course, fun is important, but who has fun when you suck?
I will also meet the ceiling and I hope I still will enjoy UT then as much as I do now! Coz I think that those nights when you suck and feel bad are as good a part of the love for UT as a good fight with your partner is a part of the relationship with her/him.
By the way, I dont't think hardware is that important. Maybe it is in the beginning, but you if you learn to use it, it makes no difference. I use A P350 and a 3 button mouse:
a=strafe left, s=back, d=strafe right, space=jump. mouse butons: alt-fire/fire/forward.
Makes forward/backward and jumping while strafing possible.