I put a cheap one in my xp4 900 a couple of months back. I like it . It is a very good learning tool. Start out on slopes that are not high. Move up the steepness of the slope {going across the slope} while you watch your clinometer and you up hill front tire. Your up hill tire will start to bounce and get light as you reach your tip point. Since you are not to high up, if you do start to roll over, turn down hill and try to catch it to prevent the roll over. If you do roll over, you will probably just be on your side with little to no damage.
This practice will give your brain practice to read the slope when you are 1000 plus feet about tree line and you have to be right in your driving. My rzr seems to be pretty stable at 30 to 35 degrees. It has been raining a lot, but when things dry out I will start using this to push 40 degrees or until i have to catch it , or put it on its side.
The terrain, size of your tires, lift, how weight and distribution of that weight is in you rzr will all be moving factors every time you get on a slope..
If any others have experience on when their rzr will roll over, I would like their input with that information.