Had a 2011 polaris 850xp and sold it at at 700 mile mark after 3 years
I primarily just use it for a trip here and there and snow plowing.
The only problem I had with it was the oil in the gearbox which caused it to stall and it took a few trips to the dealer to figure out that was the problem.

I like buying a new machine every few years so I sold it and bought a new 2014 sportsman 850 with H.O. motor and it has noticeable increase in power. Not huge , but definitely noticeable.