The only major difference between 09-12's is the dash set up and the throttle's. I personally love the 11-12 dashes over the 09-10 but for the extra 3k I was going to have to spend I wasn't willing to pay that....so instead I invested that $$$ into a sick stereo system.
Engines from 09-12 all have the option of the 255 rotax. From what I've read the 215 are dogs especially when the boat is loaded. I have the 255 and it has impressive hole shot.
As far as engine maintenance, you should change your oil every season and the superchargers should have SS clutch washers but from what I understand the S/C's need to be rebuilt every 100hrs.
Hope this helped a bit. I just joined up so sorry for the late response.