Jumping on the thread a bit late here. We purchased a new 2016 Defender HD10 DPS last March 2018. So we have had it a year now. We primarily use it for farm work on our 20 acre farm, helping my in-laws maintain their 60 acres.
The reasons we purchased the Defender was because it had three seats, unobstructed inside (no shifters or other stuff to get in the way if the middle person's feet), and the middle and passenger seat flip up when we get a dog again. It is easy to get in and ride in the middle seat, and because we routinely take our daughter or my in-laws with us, this comes in handy.
I really wanted an HD8 but I could not find any around. The HD5 would likely have been ok, but I wanted the extra towing capacity of the 8.
There was one post here about concern with the plastic bed. We occasionally haul logs, rock, tools, posts, whatever the heck junk laying around on the farm in the back with no issues. The plastic is very tough, even in cold weather (it has gotten -10F here once or twice this winter). We have the metal bed extenders on the sides which means we also have the headrack on the front, which keeps high objects in the bed. The bed also has sturdy tie downs on the bottom, and along the bed rail. It also has indentations to hold three 5 gallon buckets in place without them sliding around, and also has a bunch of indentations for separating out the bed into smaller compartments.
On it we have a front and rear windshield and sport roof to keep the weather out. It has the basic front bumper and we added the Can-Am winch. We also added the Can-Am Alpine snowplow, which is so easy to get on and off and works very well on our very steep driveway. We added the Can-Am rear cargo light as we work a lot at night on the farm. As I said, it has the headrack and the bed extenders.
My complaints is that it is sometimes hard to shift into gear until the wheels roll a bit, just like an ATV. They told me most of the UTVs are like that since they have motorcycle-like transmissions. I don't know, but it is frustrating sometimes. Also the seat belts are terrible in it. The headlight switch went out (bad contacts), so I have to get a new one (under warranty or likely will buy one myself to save from hauling it to the dealer because we use it so much). I did manage to break the bottom floor panel on the driver's side behind the wheel (I don't have the metal skid plates that you can get) by running over a large stout stick that was jammed just right in the ground and protruded through the plastic before I could stop.
If you are shopping, consider how comfortable the seating is, how easy it shifts into gear and what it feels like starting and stopping. This is hard because the dealers don't want to allow you to drive them on their lot. None of them wanted me to drive them other than maybe a few feet because they all said they didn't have the space for test drives (likely a lot of customers would abuse test drives if they could do it). I would also look at your maintenance items to see how easy the oil drain plug and filter, spark plugs, and air filters are to get to. I have changed or inspected them all on the Defender with no major complaints.
That's my 2 cents. We looked at the Kawasaki Mule, JD Gator, Kubota RTV, and several other brands before deciding on the Defender. I would do it again with the Defender but I really want to replace the seat belts because they are pathetic, they don't pull out easy without jamming up like some older car seat belts used to do.
