[Jeff76]

I have played all 3 levels and I think there actually is quite a difference between them.

I have the least amount of experience at 25NL, but it seemed pretty straight forward with plenty of loose players to pay off.

I have more hands at 50NL than any other and it is a bit more challenging compared to 25NL. The players are tighter, though not really more agressive. Usually when you get played back at people have a hand, but it's easy to play a little LAGgier than at 25NL and have a bit more fun. You don't often run into tricky players and raising limpers and 3betting light is not the norm. In fact, 3betting is KK+ about 75% of the time, and when it isn't it's most likely AK. When players DO raise (as in after the flop) they usually don't raise enough, and if YOU raise enough you'll often get people to chase their draws without the odds.

at 100NL you finally start running into a higher level of aggression. There are a few more smart TAGs who will take shots at you if you get out of line too often, there is a lot of raising limpers light, though 3betting light still doesn't happen very often. Also at 100NL you start getting raised more meaningful amounts that will deny your odds of chasing a lot of draws and people stop calling your odds denying bets as much.