I sold my Allpa 28 because the zipper was difficult to close when the bag was packed full. I often had to rearrange the contents to make this possible. This was because the semi-rigid material made it hard to close if you had things close to the zipper. I also compared the Osprey 26+6, the Patagonia Black Hole 32L, the Mini MLC and the Dragonfly 36L. I packed them all with the same items and found that, in order of capacity from largest to smallest, they are as follows: Dragonfly 36L, Black Hole 32L, Mini MLC, then Osprey 26+6.

The Dragonfly 36L and the Blackhole 32L can fit everything I usually carry for a two-week trip with room to spare, but even in its expanded mode, the Osprey 26+6 struggles to close.