haven't read all the other responses, but don't leave out the 900 ace, great trail sled, twisty, off trail unit for sure... not the punch of the 1200 on the big end, but will give the 1200 and any other up to 800+ cc sled you ride with fits in the tight stuff.... , the 600 will get by it at 80+mph, but awesome, 87 octane, no carrying oil go for a ride and have a blast doing it.... I like the 900 so much off trail, I am building a 900 freeride (900) section.... to suit my needs next season...
I have a 16' 1200 xrs I put together also,,,,,,,,,,, awesome in the trails and bumps... dont want a 2 stroke for that after riding this thing...
In the end, it is your money, get the sled that you WANT.... if you can afford it, go with your gut, you have a bunch of great choices to pick from... oh, and the 600 is a pretty cool sled too.......