I purchased this to replace an older, but smaller backpack. My old one was fine, but I just needed something bigger. It is very well designed and seems very strong. The material is appears  quite durable. The zippers stick a little bit, but not badly. I am looking forward to getting many trips using it.

Follow up: I have been using this back for about a year and love it. The zippers really present no problem. It fits well on me and is well balanced. I would now give it  5 stars. I love the division into multiple sections. It really helps me to organize what I am carrying.