I've been playing MW2 since last thanksgiving and my friends and I (all guys in their 30's)play every Saturday morning online. We get so sick of the nuke boosters and quick scopers and glitchers, but as you said, there's a counter for everything. I also think it's well balanced, even with all the flaws that have been exploited in it.
I really don't mind any weapon (nube tube, RPG, UMP, etc,) cause if you're good, you can counter any of those. But the one thing I can't stand is the akimbo rangers, those things have way too much range.
Plus, IW should fix these irritating glitches. It's not like they're new, they've been out since the game came out pretty much. Oh well, when I get bored and irritated, I just run around and kill boosters.