I wouldnt buy a Ski-doo that uses their SDI technologie yet, so far they havent had great success reliability wise with them...Alot of them blow up before they hit 2000 miles while many of those who dont, have lost alot of compression at this point, for some reasons they have serious premature ring wear problems dont ask me why but its a fact for now at least.I am sure they will improve on the system and will become very reliable in time but for now if you want to buy a Ski-doo sled id stick with the models using the proven DPM system.
The XCSP 600 is not on par technology wise with the Ski-doo REV or the Firecat 600 but will bring bullet proof reliabilty while still being a more than decent trail sled.Out of those two sleds id choose the Polaris because of the reliability factor even if in reliality the REV is a better sled.Personnally last april i snow checked a green F7 EFI Snopro,cant wait to ride the thing.