On my fourth Summit now. My 09 blew a ring at 7500km on Friday, still covered by warranty, so I traded it in on a 12 154 etec. I was riding the 12 146 the other day. WOW! So fun. That engine rips, and the sled handles beautifully. The 09 was a bit of a tank, but easy enough to handle with a bit of muscle. The 12 is a totally new beast.
Warranty has been great on all my Ski-Doos. Things are replaced very fast, and without question. I only went through 3 belts in 7500 km on that 09. I even have a hard time believing it. They must have accidentally lined things up perfectly, since everyone else I know has gone through a lot more.
I really like Ski-Doo, and I'll stick with them.