I own a Rhino, but use both at work. I have likes and dislikes of both.
The Rhino is smaller and fits in tighter places and on smaller trailers. It only seats 2 (seems like I always need more). The bed is ok unless I'm lion hunting, little small for a handful of dogs. When driving down a steep hill, the gears hold the Rhino back and you can just crawl. Its loud, hard to talk to your buddy when driving.
The Ranger is just a bigger vehicle and takes a bigger trailer to tow. Seating is better, and the bed has plenty of room. I don't like them when driving down a steep hill, if you take your foot off the gas, its almost like it kicks into neutral so you have to ride the brakes. It is quieter and you can talk while driving.
I personally still kinda prefer the Rhino.