I have just returned from a two week trip in Central Vietnam. Protected areas, workshop, and a lot of car time. This was the first time to use my new Western Flyer bag (black, with backpack straps). Clothes, toiletries, fieldbooks, GPS, gong fu tea set, oolong tea, novel, computer cables and dongles, map, Skype headphones, flip-flops, extra camera battery, cell phone, and an inflatable zafu. With enough room to even bring back a few gifts.
I am a tropical ecologist and I travel a lot to some weird places (see http://thusihaveseen.squarespace.com/). The Western Flyer is the best, most versatile, and aesthetically appealing bag I've ever used. Period. Thank you Tom Bihn.
P.S. I love the zippers.