These shoes have been great for both running and Crossfit. The only reason I give them a 4 rather than a 5 is because the fit is a little off. I'm a size 8, which is what I got. At first I thought they would be too small, because they are a bit tight across the top. After a wear or two, that got better but I noticed the toe was a bit too roomy. So I could probably go a 1/2 size down, but I feel it would too tight in other ways then? I'm not sure.
It's really not a huge thing though, they fit pretty well. Definitely a good trail/mud run shoe. Plus they look really cool.