Well, i might be able to answer that question for you.
The RZR and the Rhino cant be compared at really anything. The purpose of the vehicles are totally different.
Of course the RZR is going to be faster, handle better, and go tighter places, but the Rhino wasnt built with all this totally in mind. The Rhino is a sport/utility UTV, where its really not designed to do everything perfect. It does ok in most things, but definitely not excellent in anything. The RZRs main purpose is speed and handling. Definately not all in utility.
So, to sum it all up, both are great units. Both are designed to have their pros and cons. Its the person who uses its desicion on which is best for their lifestyle.