I used these to replace suitcases on my recent European trip. I have two Medium and one small and used them for various parts of my trip.
They stood up well to the airline's handling, were easy to pack and easy to handle.
I really appreciated the metal shoulder strap rings, no risk of them breaking under load.
An inner "document" pouch would be helpful but not necessary; a couple of small metal loops, as tie-down points could be useful as well.
Overall a great bag for travel!
Pros: Rugged, Simple, Good Value, Reliable