I bought a Kawasaki Mule 4010 after a while comparison shopping at the various dealers in my area, because at the time it was similar bang for fewer bucks than comparable Polaris, Deere, Kubota, and Honda models. Deere was $3000 more expensive. I wanted a basic model, with windshield, roof, and a hydraulic dump bed.
After using it for a year now, things I did not think about but now appreciate include a bench seat. I can get in and out of both sides easily, and carry a third person in a pinch. Some I looked at had doors; I like the easy access of no doors. I also find the bed size to be good. I can dump a tractor loader bucket of dirt into the bed without spilling any over the sides. I had not considered that, and I lucked out that my tractor bucket fits the UTV bed nicely. The Mule bed holds 4 full loader buckets of topsoil, and can easily dump and spread it with the hydraulic lift. So in this case yes, size does matter.
I use mine for farm work. I don’t go off road, and I don’t drive on public roads. Public road use opens a can of worms. You may need insurance, horn, brake lights and DOT approved headlights, DOT approved road tires, turn signals, mud flaps, speedometer, license plate lighted bracket, windshield wipers and such depending, of course, on your local laws.
BTW, I used the money I “saved” and bought a tandem axle equipment trailer. I considered the trailer buy a necessity. Where I live it’s up to you to deliver your own UTV to the local Kawasaki, Kubota, and Polaris shops for service. Deere will pickup and return theirs but for a hefty fee added to the service charges. And I can now also transport my Deere tractor myself. I added a winch so in a situation where the Mule or tractor doesn’t run, I can still load it up. I wanted to free myself of the nuisance of borrowing or renting a trailer, or paying for flatbed wrecker service both ways like some folks locally do.
