Polaris Sportsman 800 is what I had experience on.
http://www.polarisindustries.com/en-..._spsmn_800_efi
I can't speak highly enough about the absolute abuse we dished on those already heavily used beasts. When we only had 3, we would load 4 guys and all their equipment on each one for infil to our ORP. They are quiet enough to be discrete and fast enough to really help you make up ground. We ran them all over RC East and I think every one of my team's guys fell in love with them.
Here's a couple other shots of how we had them set up...