I'm toying with moving up to $16 games, and have played a few $10 regular speed games.
Depending on time and day there's still a lot of fish and bad LAGgy types. I agree about ICM players. If you can think like them, then you know their range before they push. If you see something extra loose, or they adjust to your range, then you have to adjust back.
On higher limits there's a lot more folding going on, especially SB vs BB. Since an ATC push is so obvious, I tend to adjust to push from SB a bit tighter. Still when it comes to 200/400 blinds, everyone is just as scared for their tourney as you.
There are players killing these games (according to the leaderboard) so they are also beatable.
speaking of leaderboards
http://www.pokerstars.com/poker/promotions/battle/venus/
Number 36!! woohoo! Ship that $20!