I own several products from both Tom Bihn and from Red Oxx. What I have learned is that there are subtle design philosophy differences between the two firms, even though the build quality, longevity, and service are both outstanding. To me, TB seems to try to build a little more purpose-built compartmentalization, while RO seems to focus on larger spaces which the owner can customize with accessories.

I have a 12 year old Brain Bag which I beat the snot out of for nearly a decade for both work and vacations. But as a client meeting bag, it was a little too casual as my job role changed/promoted. For that, I picked up a Red Oxx CPA about four years ago. A touch smaller and more "briefcase" looking, used the shoulder strap from my Beanos 5.5 on it and it fit better under a first class or exit row seat so I could pair it with a 22" roller. Works great with an Eagle Creek 18" folder for day trips where you want one change of clothes in case of overnight IRROPS.

When I moved cities a while back, I started flying a lot of Delta CR9s. The 22" roller was now a liability, but I decided I needed more structure than the CPA, especially when taking weekend trips. Enter the Tri-Star, where the three compartment design lets me separate clothing, tech, and toiletries/medication/etc) and it fits perfectly into a CR9/7 or E170/5 overhead bin.

Meanwhile, my Red Oxx XS Aviator is the perfect underseat bag. It is just a cavern but it totally unzips, so I use packing cubes and stuff bags to organize things in there.

Finally, my Red Oxx Beanos 5.5 is my checked extended travel bag, 8-11 days in 3-4 hotels. I use the Eagle Creek folders in the bottom half of the massive center section, and packing cubes for the top half and the two end compartments.

The only bag I have that isn't TB or RO is my Travelpro Magna 2 22" roller, after a decade of Kirkland ones. I use it primarily on flying trips of 4-7 days.