I ran in these shoes last season, and put a few hundred rugged miles on them in the Wasatch. All the good things others are saying about them I also found to be true, but I did find one real problem with them. The mesh upper is highly susceptible to tearing if you catch the outside of your foot on a root, branch or rock. I had tears on both shoes not too long after I got them. The inner liner on the uppers held out for quite a while, but eventually it tore too, destroying the integrity of the shoe. All other parts of the shoe held up well, and I could have gotten another 100 miles out of them if the uppers had remained intact.