I agree with tCook... I have both an Aeronaut and Tri-Star and given the shapes of both the Tri-star definitely packs thicker. I've found that when packed completely full the Tri-Star struggles to fit in to some regional jet overhead bins whereas I've never had any issues with the Aeronaut even when packed completely full.
Originally Posted by tCook
Usually when I travel for work I'm usually carrying my Aeronaut or Patagonia Transport MLC and another bag for my laptop and electronics (synapse 25, smart alec, pilot, or rolling laptop bag). With my usual haul of stuff I travel with I'm unable to get anything in my Aeronaut other than clothes and my toiletry kit (3-4 days of clothes, tennis shoes for working out, toiletry kit, travel tray containing ipad/iphone charger and cables). I'd be surprised if you could also fit a laptop in there unless it's a really small laptop and you only have a laptop and charger. With the Tri-star, like others, I use the center compartment for toiletries and other misc items as I always have another bag dedicated for my laptop and electronics. If I'm traveling light and it's only for a few days, I find that I can get by with just the Tri-star if I only bring my laptop and iPad but most of the time my travel for work is 3-4 days and want to bring more stuff with me, which generally rules out the Tri-star.
Anyway, in short, I find myself using the Aeronaut a lot more than the Tri-star because it packs flatter and seems to be better balanced when wearing it as a backpack.