If you'll forgive someone crashing the Tom Bihn club, I'd like to offer some love for Hedgren. My everyday bag (I prefer a backpack) is a Cosmos in navy, and my actual handbag of choice is a Milky Way in dark green from a few years ago. Incredibly tough, both of them - I've never had a Hedgren bag wear out on me in 20-odd years of owning them. Which makes replacements a seriously guilty endeavour!
If travelling with both, I put the Milky Way in the Cosmos till I'm at my seat. What I particularly like is that the back pocket of the Milky Way fits my Kindle, and the main compartment will [just] fit my noise cancelling headphones out of their case.
Admittedly, neither bag is incredibly compact, but the Cosmos is narrow enough to pass muster on Lufthansa and co when the side pockets are clipped shut. (It's only 12cm deep.)