I know 2 guys with the Polaris Ranger. Both are used for dog training and 1 additionally used for hunting.
Both guys seem to like the a lot, and they can carry lots of training gear.
Steering is just like a car/truck.
I believe the are all rated about the same, so you would just have to consider your own power, transmission (high/low range) and load capacities that you need.
I have a small Kawasaki Mule 2wd that is adequate for my needs.
I've used some others in training and working at trials, but last Spring while marshalling the Tar Heel trial I had the opportunity to use the Kubota 4wd Diesel (thanks George!) and I can say that it is by far the nicest, most solid, and most powerful of any I've driven. Probably the most expensive too.