I picked up a pair of these last week, and have worn them for riding and commuting in 20-45 degree weather. Overall, I'm very impressed with the quality of the overshoes, especially the rubberized toe. They're not the lightest, and their weight can definitely be felt turning the pedals. I'll keep a lighter pair for mild cold weather riding, but these are going to be my go-to pair for commuting, Mountain biking and bad-conditions riding. I expect them to last years, instead of months like most toe and shoe covers.
As others have said, the stops at the top of the zipper are not equal to the quality of the rest of the bootie. I stopped by a local store that does zipper repairs and had them crimp on heavier metal stops. Easy fix, minimal extra cost.