[Zybomb]

From my experience, I didn't notice as much of a difference between 2/4 and 3/6 as you seem to... both felt like the same game to me, just with slightly larger bets. The reason for this feel is from a 1/2 to a 2/4 game everything doubles in essence. Standard raises of (we'll just say 4x BB) $8 become $16. Preflop CBs of $10 become $20 etc. When you move to 3/6 things don't double, they just bump up a little bit, so it doesn't feel as if you've really moved up. I think aggression is rewarded in both games. When I was on a hot streak, a minimum of one time per session (per table) I'd limp UTG with a medium strength hand, which should clearly be folded UTG (A8s, 98s 44 KTs etc) and then limp reraise once someone put in a raise. If I was called, I'd pound the flop. Not once was I ever 'caught' making this play (this is full tables btw and used only 1x per session). Players are more aggressive, but they are also more likely to fold to your aggression when you have control over the pot not them, so you can use this to your advantage, where in the lower limits players may call with TP on the flop despite oyur preflop action for example.

The thing is I felt this held true for both 2/4 and 3/6, both games had their share of fish, maybe 2/4 had a few more, but I thought the good players were equally as good and I didn't see a huge difference in the aggression level

Not really answering too much, just rambling for whatever its worth