I haven't had this bag long enough to judge the durabilty yet, but for the price, especially compared to the outragous prices for most other bags, you can't beat it.
It's large enough to fit everything you would need for just about any shoot. I've got 3 lenses (one being the monster 70-200mm 2.8), a 580exII, a DSLR, a film SLR, and 6 roles of film in the main compartment with room for plenty more. Then of course there is room for CF cards, batteries, cleaning supplies, filters and all the other little things.
I'll be taking this on hikes and climbs in Alaska where I live, and its construction will be put to the test. So far it's held up fine.