This was a Santa Christmas gift for a really hip friend. He loved them. He also has big feet, generally wearing size 13. The largest size Chill Shoe is 12, but they fit ok, with socks, the first time. I expect they will stretch to fit perfectly.
Frankly, I had never bought anything of this brand, and they looked pretty funky when I opened the box. but my friend was blown away and acted like they were really cool. He seems to like them fine, so the gift choice was a success.