These shoes are incredibly light.  They are as close to a minimalist shoe as possible, without looking strange with separate toes.  There is no arch support, and the heel-toe drop is almost non-existent, so do not buy these if you are expecting a more traditional, padded running shoe.  You could definitely use these for long distances if you work up to it, but I was a traditional running shoe wearer before I bought these, and if I do more than 5 miles I start to feel the effects of the pounding on my joints.  Perfect for sprints, weightlifting, and the like.