When I went to college I got my first Timbuks messenger bag. I thought it was the coolest thing in the world. I would ride an old BMX to and from campus with it, and I used that bag for close to a decade. So when I started commuting to work last year and needed to get a commuter bag that could handle some rain and some sweat, Timbuk2 was a big contender.
When I started commuting I used a Jansport bag we had in the house for a while, then a hiking bag. Both were stable and comfortable, but I would end up sweating through them and having to put my clothes in a plastic bag inside the bag. That's when I started looking for a new bag. In addition to the Timbuk2 I was also looking at bags that had two shoulder straps, like the Swig backpack or the Rapha backpack. By bundling a couple deals I was able to get the Timbuk2 for a little more than 50% off ($99 reg for $44), so I figured it was kind of a no-brainer and popped on it.
SPECS: $99ish (more for special add-ons or custom) / 21 liter capacity / Water resistant generally, and waterproof liner on the inside.
The stabilizer strap was in one of the inner pockets of the bag, so I actually had to use another strap for the first month or so of commuting with the bag before I found it. The strap fits nicely under the padding. The stabilizer strap is pretty long so I just tie it further down so it doesn't flap around. I like having the large main cavity vs. different compartments, and I've never really had an issue fitting everything in. I can even stop at the grocery store if I'm not getting too much stuff.
PERFORMANCE: For some of my rides the bag works just fine. For some of them it does not work so well.
Most of my commuting is either at recovery pace or tempo. At those efforts (basically, when I'm sitting) I'm not moving around very much, and the bag stay pretty stable and feels comfortable. Whenever I need to do intervals, specifically sprinting intervals or anything standing on the pedals, the bag moves around much more than I'd like and it interferes with really putting everything into the effort. If I did I think the bag might twist around to the front (at least it feels that way), or at least get in the way between my chest and thighs.
WEATHER RESISTANCE: I've ridden this bag through rain and through wintery conditions, and have sweated on it (a TON of sweat, daily) over the summer, and it still looks pretty much like new, and my clothes stay completely dry inside the bag. It also doesn't smell bad.
PROS: Looks cool, good storage, good price, weather and sweat-proof.
CONS: Not good for out of the saddle training efforts.
RECOMMEND: This is a tricky one. I would recommend it for casual or recovery-paced riding. But the next time I get a bag for commuting I won't get this again, just because I really need to be able to those hard efforts in during my commute. I'll get a bag with two shoulder straps that can be attached together.