I think that as you move up from .5/1 --> 1/2 --> 2/4 it becomes harder to find really good loose passive tables. So table selection is really important.

In general that the players are a little better so you pay more when you make mistakes, and the other players don't make as many mistakes. I think paying attention to how people play becomes much more important, I basically just autopilot at 1/2 and that becomes a problem at 2/4 because I have found that the play starts to become more aggressive, i.e. people bluff raising more and stuff like that.

I'm not probably not the best source though I have 54K hands at 1/2 at 3BB/100, but through 18K hands at 2/4 I am only .34BB/100.