So far i am very happy with my Jammers (bought the green and blue ones). They fit pretty good, although they are a little bit short on the waist (they end right above your rear end, but i like that). In the front they are tighter and well stocked men may feel imprisoned ;).
Cant say anything about durability yet, since i weared them only 5 times. Maybe i update my review in a few months. Fabric feels very good and the seams look stabile.