I'm in the market for a new sled and I'm liking what I am hearing about the 900 ACE. I'm kicking around either a Renegade, Enduro or MXZ 900 ACE. I've owned a 95 Summit 670 and an 03 MXZ 550 Fan. I live in north-central Wyoming at 4000 feet, at the base of the Big Horn Mtns. I normally just ride around my house in 1-3 feet of snow, but make a few trips to the mountain where we have 3-5 feet of snow. On the mountain, I would say half the riding is on trail and half is off. I can't find a dealer around here with anything other than Summits. They say that the 900's would not do good on the mountain...too heavy, underpowered, too short of a track, etc. I have ridden a 95 Summit on the mountain, that is super heavy and an 03 Fanner, that is short and underpowered and did fine. I wouldn't say that I ripped the mountain up, but I did just fine. Has anyone here used any of the above models in the mountains in deep powder to give me a first-hand account of their performance, instead of a dealer trying to sell me a Summit?