I think there all the same mate. I play on pokerroom.com now, played on empire poker, titan poker, full tilt, 888 etc etc. been on loads of them!
I know what you mean about slow playing though, It really annoys me too! I think the only way to get away from it is to play bigger blind tables. The bigger the blinds, the better the players basically. I don't have the balls to do it though! I generally play 50c / $1. but play pretty tight and raise about 8 times big blind (YES 8 TIMES!) when I get A's. and maybe 6 if I get K's Q's etc. That way if anyone calls then they must have a decent hand and you'll find it easier to put them on something.
I find the best way to do it is to play really tight and play about 3 tables with about 4/5 people on each, that way you don't get bored waiting for decent hands.
If your looking for something different then have a look at www.pkr.com. Its a more graphics orientated poker site when you can design your own player and can get your character to perform loads of actions (like doing a chicken noise at people when waiting for them to call you etc). Your cards are not always on the screen either, you have to click on somehting and your player with look at his/her cards again. Which can be interesting to look out for on the flop if you know anything about tells!! The site is supposed to make the game more realistic but I think that there is a lot of things to do on it other then play poker!!!