I haven't even put in 1k hands yet at $0.50/$1.00 nl, but have noticed quite a few big differences in the play. There, also, seems to be quite a difference between the play at FTP and the play at pokerstars, but this is probably just due to the small sample size. (I'll put up a post about the difference in play between sites if I notice the differences continuing.)
Differences between 100nl and 200nl
1. Thereis a ton more limping. I have seen hands that go - UTG limps, UTG+1 limps, CO and button limp, sb limps, BB raises pot, everyone folds. I was also at a table the other night, where everyone limped, I raised 9x from the SB and everyone called. I may limp-cold call stat to my HUD. I'm not sure if there is a limp-fold stat or not, but if there is then I will probably add that one too.
2. There are a lot more passive players. I have seen more players with 50-70% VPiP/0%-10% PFR than ever before - sometimes 2 players like this at the same table. I had one guy at a table the other night that had a VPiP around 85%, a PRF of 0%, and a FCB of 0%. He always called any flop c-bet and either folded the turn to a bet or made a pot sized bet if checked to. I was amazed to see a couple of people gift him stacks, when his play seemed so transparent.
3. There isn't near as much 3 betting with a couple of exceptions. In general, if someone was 3-betting then they usually had a very strong hand. I did run into a few people that had obviously watched one too many LAGgy coaching vids (3 betting way too much) and didn't understand when other players were adjusting and how to adapt to those adjustments.
4. You need to find a way to note the regulars. There are definitely some good regulars playing 100nl and it helps to make a note of who they are. There are so many more good games to choose from at 100nl. You shouldn't be sitting at a table with some of the better players at the limit, unless there are some fish at the table that you are targeting.
I'm going to try to start saving some hands to illustrate some of the differences.