Very comfy. These are my first set of reefs, but I've heard very good things about them. I thought I had measured my feet according to the website's &#34;size guide,&#34; and even going up half a size, they were still a tad bit small. They ended up being just a tad big for my growing daughter, and since they were on sale, we decided to keep them for her. I just bought another pair a size bigger, so they should fit reasonably well when they arrive. The sale was even better the second time around! The sizing has been my only issue thus far. Hope they turn out to be as durable as I've heard.