Longtime Doo rider (ok, not not long time but 12 years) looking at another option for my wife. She currently rides a Summit XM 600 146 converted to 154 but after watching her ride and knowing her tendencies, I think this sled is not exactly right for her as she does not do mountains or any kind of steep terrain but she loves playing in the deep pow. We also ride with some older friends that mostly trail ride and I want something that will be comfortable for her on the trail which the Summit is not (I've got an Expedition for trail rides). So I'm considering getting her a snow check Assault for next year. My questions are, how is the 850 motor holding up, is the new MATRYX chassis better than the AXYS for riding deep snow and lastly, 1.6 or 2.0 track?