Why do you play no-limit? Why do you play limit?

I feel like I have a lot more control at NL. And my variance is usually pretty low b/c I play quite conservatively (and it works at small stakes). However, it can get pretty boring waiting for that "action" hand, so I need to 8 table just to keep myself occupied.

Recently I haven't been doing well in limit, and thus the variance has been a biotch. However, I like the speed of 6-max limit and all the betting...but for some reason I just don't seem to have a knack for it (even though my strongest point is math). And I can't figure out if it's b/c I'm too aggressive or not aggressive enough, if I fold too much or what. I've been beating the $1/$2 6-max tables at Party, but am losing quite significantly at the $1/$2 5-max tables at PokerRoom, and am wondering if it's that much more difficult or if it's just variance.