Pokerstars differences between 16,27 & 60 dollar turbos

I have been a low buyin SNG player for about a year. For the past 2 months I've been doing the 16 dollar turbos and keeping a very good ROI and ITM. My bankroll is ready for the 27s and might soon be ready for the 60s. What I'm wondering is if someone could give some analysis on the different levels of play. What will my opponents be doing differently and what kinds of things should I be doing differently? How long should I stay with the 27s before I go to the 60s? Any kind of info is appreciated. Thanks.