I used to own a 2010 Tundra Sport 550f. I currently own a 2012 Expedition Sport ACE. Unless you really need the narrow stance of the Tundra, I would recommend the Expedition instead.
The wider front end and significantly greater suspension travel make a huge difference in rider comfort. 16" X 154" track and ski skins provide crazy floatation, I have yet to stick this sled in the slush.
And you are going to love the ACE!
Beat sled I have ever owned.