I did a 5.5 hour training run in these shoes and thought the shoes really held up nicely. What I am bothered by these shoes though is on the top of the shoes, near the pinky toes, they rub my the of my pinky right toe raw. There is something in the stitching which doesn't feel right. The shoes are true to size because of the wide toe box. So don't go up 1/2 size, otherwise, it will feel like clown shoes. :)
I am training for Leadville 100 this year. I will not wear these shoes for the race. I think Montrail as whole is a great shoe company, but if it weren't for the flawed stitching at the pinking toe area, I might have considered using them for Leadville because the Rockridge Trail were great going up and down Barr Trail towards Pikes Peak. Even did great in the snow! I guess it really comes down to the shape of your foot. Others out there swear by these shoes and that's cool too.