I purchased the S flares for my 08 RZR. They help better than the stock flares, of course, but they don't keep all the mud out, especially the bed. They are plyable, and flex O.K..
There is one thing that I did not like about the mounting. The kit that I got, supplied the plastic push pins for the mounting holes in the fender well. These do not stay in well, and there are only 2 holes provided. I went to the dealer, and ordered 3 of the speed bolt fasteners for EACH fender. I believe the S comes this way. You have to cut the plastic just a bit for the speed fasteners to line up with the old mounting holes. I wish you didn't have to do that so more material would still be in place. They conform to the body well, and look real clean.
For those who are thinking of purchasing flares, I would be concerned as to how plyable they are, and how they mount.