I own a CanAm (Bombardier) 800 Max (two up model), and have installed the CanAm Apache track kit on it. I was fortunate to find the track kit a year old used, and saved half the money. My impressions: Speed is reduced by about 1/3 with this kit. So top speed is about 50, ehich feel VERY fast. Steering is more difficult than with tires. Steering is impossible when stopped, you must steer while moving. While moving, it is not a big problem. My wife operates and loves it (OK, actually the whole idea was hers to begin with). In four wheel drive mode, it rarely spins a track, even though it has about 65 horsepower available. Nothing will stop it from going through snow. It is not really like riding a snowmobile, since you are sitting upright, and more exposed to the wind, you get cold faster. Definitely HAVE to have a windshield on there. It actually floats in moderate density snow. For instance, she and I went riding one day last winter. She took the CanAm, I rode my two wheel drive Polaris sport machine, just for fun and to see how far I could get. Of course there was a limit to my two wheel drive, and soon I was stuck where the trail comes out of the woods near the top of a hill and crosses an open field. The snow drifted there about three feet deep, and nothing had disturbed the snow, so it was really soft. I stopped as soon as I saw the deep stuff ahead, and I was trying to get it turned around so I could go back, when she came blasting past me, right through all the deep stuff, and on across the field. I figured she'd come back, but did not for several minutes, so after I got my machine turned, I started hiking after her. I had to walk about 200 feet through the deepest snow, around a corner and up the hill a little, to find her. I was wading, almost swimming in it. Snow up to my crotch. I noticed her tracks had sunk in about six inches. The machine weighs about 650, and the tracks are about 60 pounds each. Certainly the gross weight on the whole rig with operator was over 1000 pounds. I caught up to her, and together we rode back to my machine, again barely sinking in. Plus, clearance is greatly improved over tires, because the tracks raise the machine about 6 inches. I think our has almost 15 inches of clearance at the frame (less where the suspension comes downward on each side). The thing will pull like a wrecker too. I built a neat tow-bar deal to pull snow-sledders back up the hill (need pics of that for you). And I pull a homemade groomer around in the snow almost constantly. Once the tracked CanAm goes through, pulling a snow drag groomer, the snow freezes and then I can ride sport atv machines on it almost all winter. This activity is on private trails. Unfortunately the way "snowmobile" is defined, the tracked ATV is not legal on public snowmobile trails. I bought a snowmobile trail pass for it last year, and rode it just twice on public trails, but was informed by local club members that it was frowned upon. Too bad, it does less damage than a sled, which can easily pile up the snow when launching. It is leagl on frozen lakes, so I plan to take it over to Lake Zumbro on a nice day this winter, if the ice is safe.
My take is, the snow is so unpredictable, I hate to have a snowmobile or two setting there year after year waiting for use or hauling a couple hundred miles for use, this make much more sense. It is a blast to ride, and very big and comfortable for two people. On a nice day, after a fresh snow, with low winds, and you dress for the occasion, it is the greatest feeling to be able to go anywhere and enjoy the scenery with my honey.
To somewhat answer the UTV vs ATV question: If the UTV had a little cab enclosure, maybe even a heater, and you put that on tracks, I would say the experience would be even better. Side-by-side seating has advantages of better communication, easier to point out the terrain and wildlife sights, etc. I have looked at the UTVs but they are so very expensive and the track kits are then twice the money too, so if I add it up correctly it would cost me about 17000 to have a tracked UTV. My Can Am is an '06 and I got a great price on that, plus the half-price tracks, so I have less than 10000 in the whole package. The hauling capacity of the little dump box on a UTV is certainly attractive also, so eventually I would think that would sway me after this ATV wears out.