The previous reviews on these are very accurate.  I typically wear a 11.5 in running shoes, bought an 11 in these and they fit just a little loosely. That worked out because there's really not a lot of support so I used an insert with them.  My first time wearing them was an 8.5 mile run and I thought they held up better than expected but the bottoms of my feet were starting to hurt by the end.  I got them for a spartan race and they look like they'll do the job but otherwise wouldn't get them for every day running. Overall, a pretty solid deal for the price.