07 and 08 almost identical other than 08 sno pros come with the float skid. Think there is an ecu map change to help hot starts, but that is about it.
09 is a different animal. Cleaner map, electronic engine reverse, powerclaw track, tunnel is 6" shorter, LED break light and redesigned tunnel section, and 22lbs lighter than 08 chassis. sno -pros also get the adjustable riser and premium gauge w/ altimeter.
The 09 is where it is at.