I've vacationed in the Rocky Mountain high country of Colorado for 35+ years. SxS are the worst enviromental thing that has happened to the high country. Extremely hard on trails because they are always spinning and tearing up the fine material on those trails which causes severe errosion. This Summer I was on a couple trails that I hadn't been on for 8 years. The damage was horrible. To imply they are better for the environment is simply wrong.
A SxS will make the trip quicker than a Jeep or Sami. But it required a heavy duty pickup and a trailer to get there. At the end of the day this combination is not environmentally friendly. Handy, but not better.