They look to be a step up from golf carts - much more sturdy and durable, probably less likely to roll over unless you do something stupid.

If an NEV like a GEM is street legal, I don't see why one of these shouldn't be. Not for highway use, though.

Side by side ATV's (and even regular 4 wheeled ATV's) are now street legal in Utah:

http://www.epicmotors.com/ATVs%20Now%20legal%20in%20Utah.html

The reality of ATV's is similar to the reality of most large motorcycles. They don't get great gas mileage. 20-30mpg is the usual. Of course, when you ride an ATV you normally are not driving it like you are in the Mobil Mileage Rally.

I talked to a guy in Moab who was out driving his Polaris Ranger. He said since the law was passed, he hardly ever drove his truck. Of course, Moab, Utah is pretty much the perfect environment for an open ATV. I doubt you would see a lot of people driving one of these in Dallas in August, or Chicago in January.

I get sticker shock. And I wonder about durability. Will they get 200K, or the hours of a tractor?

Right now I see them mostly as status, highly visible signs of affluence. Last winter you could hardly keep them in the showroom, wonder what goes on this winter.