Well the good news is that all the sleds you mentioned will rock! I ride 07 m8 and m1000, but ride with an assortment. I think the Dragon is a fun sled but I don't think much of the fit and finish that Polaris is producing right now. If they can't get the hood to fit on the side panels what else haven't they done well? Also I think that Pol 800 gets too much credit. It looks good on paper, but the one I rode was smooth but not much for the giggle factor (i.e. Torque). BUT it was bone stock. I will say that the Dragon rides very nicely, but so does the Cat. I can say the Cat 800 with Y-pipe and can rocks, and the 09 is better still. I don't think the chassis can be beat for all round rallin'. The Xp probably offers the most power to weight, but its' such a weird chassis. But so what, right, you'll get used to it. The cat and Polaris chassis' are basically the same geometry, and the XP and REVs are rider forward. I think all of the above come with pretty good shocks, the Assault, or Cats HCR should have better shocks but both will have very hard composite tracks. Also consider the dealers that you'll deal with. So clearly a bit biased but those are my observations.