I have not tried these boots but they are rated to be comfortable at -40, just as the Artic Sport's, I purchased two years ago. Some noticeable differences: the commuter's are much narrower and feel like they have a lot less insulation. They look sleeker, but will they be as warm? Personally, I'd rather have warmth over style any day. I suspect that the commuter's won't be as warm as the old artic sports, which have insulation right up around the calf, but the commuter's do not. I got the commuter's on clearance thinking I was getting a deal...We'll see how it goes this winter in Madison..