the machine that will serve you best depends totally upon your intended uses. the specs tell the story. the two machines are designed for different purposes and thus arent truly comparable. the rhino is a recreational machine with good utility value. a ranger is a utility machine with good recreational value. if your focus is recreational riding with some work, the rhino is the better choice. if your focus is work with some recreational riding, the ranger is the better choice.
I know that this is an older post, but thought that people that are searching in the future might find this info helpful. There is a quick comparison chart here: recreation utility vehicles comparison. It compares several of the most popular RUV models availabe. I have been shopping around for recreation utility vehicles for a long time and have done a lot research. Personally, I think that the Yamaha Rhino is probably the best choice out there right now. That might change in the near future, since there might be some new utility vehicles coming out from other manufacturers that are better. For now, the Yamaha Rhino is my personal favorite for all around best trail riding and work machine.