When my wife came home with this I was a bit dubious. That we have now bought another one -for me as I kept nicking hers - is a testament to how handy it can be. It's fine for its main purpose for presenting a clean-lined bag to prevent it being snagged by airport handlers and it adds to the security of the contents as you can lock it easily with an "approved lock". At the other end, if you're not yet ready to take out the inner rucsac, whip the carry strap out of its little pocket you can then sling it diagonally over your shoulder. The bag's made of tough, light nylon and easily stows into one's rucsac. The zips are good quality and the main one good and deep. Seemingly robust attachments.
Where it really comes into its own, however (and this is the bit I didn't recognise at first sight) is as a spare (and lockable) sac for extra kit when you are off onto your side-trip (or even main trip) and want to leave some gear behind. Or even keeping stuff together in or around your tent or hotel room. I can't really think of anything that would improve it.