Brant,
I found your search for the 'perfect backpack' very interesting. I also found it exhausting that you had to spend so much time searching for that perfect bag. With hundreds of choices available (and I don't recall a price limit) it troubles me that not one company can meet your needs. I 'only' have three bags, and all three are far from perfect, I suspect most others on this site have at least three bags. Hopefully, at least one manufacturer is following this thread and comes up with a backpack that would meet your (and many others) needs as a result.

I've traveled on airplane trips about three or four times a year for the last four years (three international) and it appears that you fly much more often. For what it's worth, no one has ever measured or even commented on our carry on bags. I typically carry my Mindshift FirstLight 30L with tripod attached to the outside. Two flights were from JFK and the rest were from EWR.