Its easier to replace belts than engines, or drive shafts.
Haven't ridden a PC, but right now if I were in market for a sled after riding a Pro 800 for a couple seasons. I'd be looking at the 13 XM, 13 PC, or 13 Pro 600 [that is of course if the drive shaft issue gets resolved properly].
I'd get a feel for the chassis first (all 3), I think they are all going to work very well/similarily.
Again, don't get me wrong, I love the Pro chassis, it still amazes me.
But if Doo did their rear suspension right (for reliability) I think they are going to have a winner...regardless of the extra ~40 lbs. Same goes for the refined 13 PC.
I hate 2 stroke engine issues, thats why I left Doo for Yamaha years back... I gave the Polaris 800 a try and was dissapointed with its reliability.
Cat n Doo seem to both have the more reliable engine..with more power.
Doo also has the bonus of low oil usage.
The Pol you'll have to turn up the oiler and still run a bunch of oil in the tank if you want to try keeping from having a dead engine every season..
-Just another disgruntled Pro owner who loves his Pro....yep, the chassis is that good in my eyes . . . But I think the others are very close now...