I wanted a large-size backpack that would also roll. This fit the bill perfectly. Tons of storage, and perfect size for a carry-on. My complaint--and reason I returned it, was that the Velcro flap that holds the back guard to the bottom of the unit (when using it as a backpack) started to tear off just after a couple of days of using the unit. This was a real disappointment, and I questioned the quality of the rest of the seams--so I ended up returning it. Amazon is great with handling these situations though. I'm definitely going to try a similar pack.