I own these two:
I personally don't find the NF Jester to be very good; it's too small and not sturdy enough. There's no back support and it's rather over-priced for what you get. But it's sufficient for me, and it looks pretty good. Personally I would have gone for a Box Shot if I could've found one.
As for the Timbuk2, I have nothing but good things to say about it, except that for some reason, when I'm carrying a lot of stuff, the strap squeaks if I'm walking. With every second step it goes "creek!" and makes this annoying squeaking noise. Not sure if it's the bag or if it's just me doing something wrong?
Another thing is that I wish the strap tightened a bit more. When I'm not carrying much stuff and I'm cycling, it can shift around a bit and swing around to my front, which is rather dangerous while I'm biking. So I make it a point to make sure I have a decent amount of stuff in the Timbuk2 if I'm going to be on my bike. Otherwise the strap is too loose and it tends to shift on my back.
Good bags overall, however.
I think in the future I might get a Dakine or a higher-end North Face. For messenger bags, I can't think of an alternative for the Timbuk2.