I've been looking to upgrade from my black messenger bag to something a little more professional, especially since I'll be in schools a lot more this year. However, since I will be a teacher (hardly an environment where formality is required), I wanted something that was still a little rugged. The obvious choice was Filson. I was originally looking at the 256, but figured that would be too small. Then I wanted to get the 257, but it was a little more than I wanted to spend. Then, when I was last on Crane's website (great store and place to shop, they took care of me), I saw the new "Passage Luggage" collection, specifically the Saddlebag Briefcase. That's what I got and it is awesome.
When I take it to class, I'll use the shoulder strap (kind of like a messenger bag), but when I go to schools, I'll carry it by the handle and tuck the strap in the bag. A bit more professional.