I've been looking into this Tortuga pack a bit:
http://www.tortugabackpacks.com/prod...ravel-backpack
The shoulder straps look a bit wimpy and it's quite box shaped but it seems to have all the other features I look for in a travel bag. I've been looking at the other bags on your list and the 3 I'm trying to decide between are the Tortuga, the Osprey Porter 46 and Gregory Border 35.