i went with mod skis and love em. i've had simmons and they are really hard to turn slowly. mods sidehill awesome and you can change parts, not just the whole ski. plastic wears down and you can just change that, not a new ski. saves $$$ and they simply just kick a--! you wont be dissapointed.
X2, Mods are the best pure powder ski out there (and yes, I've tried the others including Simmons gen 1 and 2, Powder Pros, etc.). If you also do some trail riding then the Mtn Pilots with Shaper bars are actually a pretty decent setup for both on and off-trail.
Pilot 6.9 on my 04 Rev. Carbids on middle and outter edge. Great all around ski. I loved-hated my simmons. Great in the deep powder , darted every where on the trail home and the second time the simmons hung on the deck and pitched me off they were gone. Dont know about the other skis mentioned here. Dino
Pilot 6.9s - all you need are the skiis, everything else moves over from the old ones. Had the Mods and they weren't bad but the Pilots are the cheapest route and in my opinion, the best (got 'em on my '04)