You're not going to go wrong with either one. I went with the MDT LSS chassis to save on weight. However there are some limitation to that chasis. The forend is short and is all aluminum. If you plan on shooting in the cold, you will have to keep that in mind. The metal forend will sap the heat right out of your hand. Also, you shooting this chassis freehand is a challenge. You will touch the barrel; I'm shooting a varmint profile CBI 260 barrel. Again, I was looking for the lightest weight chassis system I could go with. The XLR carbon chasis was outside of my price range.
I would look at the MDT HS3 chassis. It weighs a few more ounces but mitigates many of the weaknesses of the LSS.
http://i644.photobucket.com/albums/u...psqxp07aly.jpg