I purchased these for my son. He uses these (size medium)with his 11-1/2 Vasque breeze2.0. And the fit is excellent. I was worried that they would be to small. I have worn a pair for 3 years or so. They have proven to be durable. I believe any gaitor will help keep your feet a bit warmer as well. Great product IMHO!
I have these along with the OR croc's and these are lighter, more breathable and seem to perform better no matter which way I cut it. You would think that the more expensive of the two would be the better performer but in this case, the cheaper one wins every single time. I was able to stay dry on the AT in December trekking through snow well past my ankles without even a drop of moisture entering my boots. At the end of the day, gaiters are like fishing wadders, you can go without them, but once you try them, you'll never go back.
This is the only pair of gaiters I have owned, so I can't really compare them to other gaiters. I do know that they are great for stream crossings, hiking in snow, or just keeping dirt and rocks out of your boots.
These gaiters are great. Super light weight and they keep the water and snow out! If you hike a lot in the snow then this is the gaiter for you! If you plan on climbing technical snow and ice with crampons you may want to upgrade to a thicker material. Otherwise keep it light and keep it simple with the Verglas.