Ok, to cut to the chase, these shoes saved my ”butt “ this winter. I am 10 days away from Marathon des Sables and without them would not have been able to train effectively for the last five months. I can’t handle a treadmill I needed a shoe that could get me through one of the more brutal winters in years here in Moscow. The Sacony Razor did not disappoint. From my perspective the key is the outer Vibram shell. Leading up to Christmas I had a self imposed cut of temp for running outside at -20c, as such I missed a few days. Post holidays the temperature rarely got above -20c, my limits changed accordingly. Not the temperatures to acclimatize for MDS but I had to get the mileage in. My coldest run was a 20k at -26c, start to finish. I wore one pair of heavy Fox River socks and that was it. My feet never got cold, not even the ends of my toes. Other long runs, up to three hours at -20c yielded the same results. I could not have gotten the same outcome with any other shoe/sock combinations.
In addition to the warmth these shoes are water proof. This past weekend we had a fresh 30 cm snow fall followed by a “flash” spring. A total “slush fest” . Near ankle deep freezing water and slush in my jaunt through Gorky Park. No issues though, my feet remained dry.
Now the traction is good, have seen equivalent or better on certain trail shoes, and they are a bit heavy, which is what expect, but the bottom line is they keep your feet warm and dry, and in the dead of winter that’s what you need.
These are a “must have” anywhere there are winter conditions, I assume that means most of Canada.