Thanks 1bush2hog, I do have experience on at least the Gator, RTV and Rhino. I was first a Gator owner, then a RTV owner, and now also own a Rhino. Please don't construe that I don't like the JD machines, because I do. The RTV is just a heavier work machine for my particular needs.
Now, for what the original poster wants, I'll have to agree that the Rhino is definitely what you want. With a few modifications, my Rhino will run with all but the most radical and extreme ATV's. It will outrun most all of the "utility" ATV's and the Rhino has over 7" of wheel travel at each wheel to keep the power on the ground. I can give you a true white knuckle ride in the Rhino, and it will also tow a very heavy trailer and haul around 500 pounds in the back up to 50 mph no problem. A good buddy of mine has a 500 Polaris ATV and I can out run him. And, I don't consider his Polaris any dog on power.
I have climbed hills that my ATV friends simply passed on trying. As you know, an ATV will definitely roll over backwards on a really steep hill. And, if you're not a skilled rider, the ride back down the hill after it's flipped will be, well, let's say, adventerous. I've not been able to get the front wheels up on the Rhino on any hill, or from a stopped start.
In my past, I raced the 250 and open class of motocross for several years. After that, most everything seems slow. With a few performance mods, the Rhino isn't nearly that fast, but it will give two people a pretty good thrill ride. I just don't recommend jumping it. Yeah, I tried that. /forums/images/graemlins/blush.gif The 7 plus inches of travel are great while you are on the ground, but you take a 1000 pound UV with two 200 pound riders in it, and the landing isn't quite what you'd want. /forums/images/graemlins/crazy.gif
The Rhino isn't in the same league as the RTV or the HPX Gator on doing work, but they are not in the same league as the Rhino on the "fun" factor. Oh yeah, the Rhino will go anywhere my ATV buddies can go except between really tight trees. /forums/images/graemlins/smile.gif Good luck!