@boltzmannsbrain - I have experience with Deuter.
I own a 28L Deuter Futura. It works great as a daypack, for around town, or for traveling. It's well-constructed and popular in Germany (to me, a good sign for durability). The big selling point for me is that that the frame holds the pack an inch or so off my body, important since I sweat a lot in even cool weather, and don't relish walking around with a big splotch on my back. It also includes a raincover in the bottom of the pack. The size is just right as well, it's small enough to be easy to carry around, but large enough that I can stuff a ton of crap into it. I spent a week backpacking in Europe with it last year, and will be spending two weeks traveling with it this year. I don't anticipate any problems, but I do travel light.
I'm 5'8", the bag doesn't feel overly large to me.
My previous pack was an army surplus pack (I think it's an ALICE pack). Super-durable (I used it for 5 years with no signs of wear), but it was not well thought-out, IMO. There was no support so it was just a big pouch, with some water bottle pouches on the outside. If you didn't put something solid in it, it would collapse. Also the clips that it used were very difficult to quickly open/close, I had to replace them with some simple snap clips. Finally I felt self-conscious wearing it, since I haven't been in the military and didn't want to pretend that I was.
Army surplus is probably the best deal in terms of cost/durability ratio, but not so good for usability/style.
I've been happy with the Deuter and have no desire to switch right now.