Have one, and while spacious, I've never felt well organized with it.

These days I'm carrying an eBags Professional - laptop space, center tablet pocket that can be accessed from top, pocket for files/papers, bottom hard compartment for charger, reasonably well organized pockets for pens, usb drives, etc, and most importantly for travel, it has dual carry-on handle pass throughs.

The Brain Bag by itself is not well organized, but add a Brain Cell to hold the laptop, a Snake Charmer for cables, and a Freudian Slip for papers and you're getting somewhere. You're also getting spendy, so there is that. But the bags last forever and show great attention to detail in their construction. (Another risk is that you'll soon find yourself buying a Bihn travel bag, briefcase, etc...)

I have the Brain Cell.

The eBags Professional Weekender looks interesting.

I was also looking at an Osprey: https://www.amazon.com/Osprey-Porter-Travel-Backpack-46-Lite...

Looks great, but they currently aren't selling any.