I dont own one but 2 friends of mine have 900Rs 1 Mach, 1 X package. They both are quite happy with the sled but both of them were expecting more performance wise. A properly set up BRP 850 will show the 900 its tail lights and a new 850 Polaris will dust both of them.
1 is keeping his for another season, the other is going back to an 850.
I am going away next week with the guy with the X. I told him I would like to try it for at least 50kms. I am sure it will be awesome on the big northern Ontario trails.