I think your and my issue is the same, Tom’s travel bags tend to be too compartmentalized and limiting. I have a Tom Bihn Synapse 25L backpack and use it as a business every day carry. Love it and the workmanship along with how it fits in airplanes. I also purchased a Tom Bihn Brain Bag for my niece and in retrospect I kinda wished I had purchased it for me but it would be tight under many aircraft seats.

However for clothes and toiletries I either use my RedOxx Skytrain or Mini Boss. They are perfect for the trips I take.