How about an Expandable Imago ?
I was rummaging through my Grad school memorabilia yesterday and ran across my first Messenger Bag the MELO ! It looks as though it was hardly used and yet I lugged a ton of books on long hikes between transit stations from home to school and back. I reckon I did this for 300 days or so often in the rain and snow. Not a stitch unraveled and there's just some light abrasion on the bottom. I know I've washed it at least a dozen times. The most conspicuous feature of this bag is it's expanding zipper!. I'm not sure if any Tom Bihn bags have this feature but I loved it and would really like to see the next iteration of Imago have it . I say this because although it's easy to plan the Imago's contents at the begining of a journey- it's amazing how much stuff we can pick up on the way home!