I recently got a Smart Alec as an EDC backpack and laptop bag. I'm very happy with it, and it's gotten me thinking about replacing my carry-on sized luggage with a Tom Bihn bag, probably an Aeronaut. However, from what I've read, one of the best features of the Aeronaut is how well it works as a backpack. If I already have my back occupied by the Smart Alec with the laptop, would I really be able to take full advantage of the Aeronaut? How well does the Aeronaut work as just a shoulder bag?