I bought these to compete in a desert half marathon. As I don't live in the US I had to trust the NB sizing charts, and was disappointed for the first time with the NB sizing. I am a 9 1/2 in NB's, and in the many pairs I ordered in the past never had a problem. These run almost a size too large. In other words, I am forced to run with socks to prevent blistering.

I recently bought a pair of M730 minimalist runners, and they fit like a glove.

Besides the sizing Issue, these are great shows. I would not count on them for running on sharp rocks, the front of the shoe does not offer enough protection, which would leave you with bruised feet at the end of a long run. For anything that is not jagged rocks (or large thornes) you should be fine. These offer great grip, a good amount of cushioning for a minimalist shoe, and seem to be well made so far (3 weeks of mild use). For more serious trail running, especially if you are looking for a shoe that will last for a while, go for the Merrel Trail Glove. They are considerably more rugged, and have a more robust shell.