I have owned a pair of Shiver Mocs for two years and am extremely happy with them. They are very comfortable and warm, but not too warm to be worn indoors. I wore the Shiver Mocs the first year when up skiing at Lake Tahoe. Great for to and from putting on my ski boots and when out and about in the cold. This past winter I worked at Heavenly Ski Resort and wore them almost every day working outside, on my feet for 6-8 hours, at the base of the gondola there. They were very comfortable and the light insulation was perfect with a pair of Smartwool socks. It was a warmer than usual winter and the insulation in the Shiver Mocs was just right. I just used thicker socks when needed. The tread is aggressive and "sticky" which provided excellent traction on the snow and ice. The shoes are still in excellent shape and I will be wearing again next fall and winter. A note on sizing.... My size in these is a 10R, though uninsulated Jungle Mocs fit me in a 9.5R. May be that the insulation takes up an extra 1/2 size or the thickness of the socks worn with it. I highly recommend the Merrell Shiver Moc 2 for wear during the winter months.