So here is my spill on UTVS. There is a range from work horses on the left to more off road/ sporty utvs on the right.
On the left you have your old Mule 3010s and 4010s, some of the Gators, and some of the Kubotas. These units are for work. They tend to have heavier suspension, be designed for fairly flat, hard packed areas. You give up speed and some off road capabilities.
Sliding to the right a hair most of the brands I named off like JD, Kubota, Kawasaki all have an IRS, CVT machines. They give you a smoother ride, little faster speed, and are still very work oriented. My personal favorite the Mule Pro falls in this category. These machines are still very off road capable and will do more than most farmer/ rancher people are willing to do.
Sliding to the right a little more you have machines that are aimed more towards speed, off road performance. Its not that you can't work out of them but their focus is shifting and it drives up the price and adds some bells and whistle that IMO are necessary for a work unit. I would categorize the Polaris Ranger, the Can Am, Honda Pioneer and Yamaha has a few in this category also.
Far right are you is your sport machines like the RZRs, etc.
If your in an are with a lot of snow, steep hills, where those off road capabilities are a priority the third category is probably the way to go. If you want to work it hard and are really going for reliability and such the second category may be a little better.
I am not a Polaris fan. From owning and operating Rangers for a good while my experience has been they have more part failures than other brands. They make a great product but you will be working on it more often then other brands. Im a big fan of the comparable Can Am unit and the Honda Pioneer. They are both great quality machines. I know quite a few die are Polaris families going to Can Ams and Hondas.
I personally run the Mule Pros for several reasons. They have a great balance of reliability and performance. They can still be had at a reasonable price. The bed conversion deal is invaluable to me. To be able to hold 4 people and then work by myself and have the bed space is great. That leads to my next point of its turning radius and the agility of it. I can still go in barns, thru cattle pens, around the brush and trees... with 4 people. Most all the other 4 person units are very large and you give up a lot of that.