I've read the "Best man bag?" thread with great interest. I have a related question.
I'd like to buy a Bihn bag that would serve well both as an everyday man bag, and as a personal item on the airplane.
My Brain Bag has done great service as an everyday bag, but it's really much, much larger than I need for that purpose.
My experience has been that even a backpack as small as my Smart Alec triggers the "second bag" alarms in the brains of airline staff, so I'd like to find something even smaller. Where I live, most of the flights out are on RJs, which means the airline staff tend to be even stricter about carry-ons. My normal strategy is to pack clothes and my CPAP into my Aeronaut and take a second smaller bag for under the seat, but several times I've ended up having to play the "my CPAP's in the red bag and my laptop's in the other one, so I can't check or gate-check either one" card. I'm kind of tired of those discussions, and of having to worry about them when I fly.
This new bag may not need to hold my laptop any more. I'm planning to take my smartphone on future flights and leave the laptop at home.