You cant really compare a Gator RSX 850i to a RZR 900 XP. That's like comparing apples to oranges. If I was going to compare to a rzr it would be the 800 or 570. With that being said, the RZRs are PURE SPORTS, the RSX is a SPORT UTILITY.
If I was going to compare my 2 rides, I would say for work I would go with the Gator everytime. For fun, its a toss up, it depends on what I am doing. They are both great machines and fun as all get out.
Yes, the RZR 900 has more power and better agility, like I said its PURE SPORT.
The Gator RSX has great low end torque, it pulls like a mule on steroids. Top speed sucks, but in time I think JD will improve on that as there SXS evolve.
I can throw the rzr around more than the gator, but the gator will throw around more than most if not any UTV.
There is times I will take out the RZR more than the Gator, or there is times I will take out the Gator more than the RZR. Then there is times I will take both out and ride one more than the other or switch up. Usually when I take both out, a family member or real close friend is driving one.
Hope this helps, keep the questions coming.