Yeah Oldie, get UT2K4 running.  Then get TAM Arena Master setup.  Then prepare to get your ass kicked by EVERYONE.  The level of skill in this game is rediculous.  I'm still trying to get use to the differences (low gravity, jumping over people's heads when fighting, jacked up sound, shield gun, etc.)  But it's a load of fun.  As far as the number of cheaters, I have no idea.  But I know at least a couple of legit good players that make it worth playing.  One of which is Xmid.  Guys like Illusion, UsaPride, Kokuieu, James, Tierce, etc. I don't know about (but they will hitscan you like no other).