Performed very good
I bought these gaiters for a NOLS backpacking course in Alaska. I was surprised by their waterproof ability. When the river was below the blue section, no water entered my boots. The sole strap stayed in perfect condition (unlike my boots!) and I didn't even buy those protectors most people had. Overall, they held up very well and still look brand new. Other people on my course did not take as good care of their gear, though and their gaiters looked pretty worn by the end of the month. As for sizes, I am 5'5" average build, size 8.5 boot, and the medium fit perfect.