I bought this rolling backpack almost 2 months ago to wheel around a TON of books for school. I wasn't sure it would be able to hold all of them, since my old packback couldn't (8 big, thick books.... I wish I could include a picture!). Anyway, even without using the expansion, this backpack held them all with room to spare. Since I can't lift the backpack when it's loaded, I rely SOLELY on the rollers and they have held up well and so easy to manuever. Also there is a flap that covers the wheels for clean storing in my car, which I really appreciate!I can't say enough positive things about this backpack. For under 40.00 dollars, it can't be beat. I looked at others costing over $70.00 and they can't compare. Hope you find this review helpful, and if you buy one, I'm sure you won't be disappointed.