For a while I used by Timbuk2 Shift pannier with my vintage mtb commuter. Then I started using my folding bike and CX bike more, so I started using my Osprey Momentum backpack instead. And my wife commandeered the Shift for her cargo bike. Been really happy with the backpack, but I happened to find a Timbuk2 Cog pannier at Nordstrom Rack for $50 and they were able to order me one from another store for the same price. It's a nice commuting pannier, roomy, has a padded laptop sleeve, and a shoulder strap to detach and take with you. I loaded it up yesterday and rode my usual commute. With the 90F+ heat in Chicago right now, it seemed like as good of a time as any to see how I liked not having a backpack. I also bought some stuff downtown and went home with full panniers. The question is, would I become one of the converted? Would I start answering every thread that asks "What backpack should I get?" with "None. Get panniers instead." as others on Team Pannier do?

In short, I can say a pretty definitive no. Not for my commute. I'm often threading through downtown congestion, hopping curbs (sometimes at oblique angles), swerving around glass on the MUP at speed, etc. The effect of all the weight being on the rear wheel rather than on my body made these maneuvers much less sure. A lot of things I would have done on the bike I avoided because it just didn't feel right. I tried to hop the rear wheel over a 2" lip at a 30 degree angle and instead it just slid along almost causing a crash. The bike felt much less like a single rigid machine than a front end and a back end that sometimes were doing two different things. And it was warm enough that I had to change my shirt when I got to the office anyway.

I get the reason for choosing panniers over a backpack, and if I'm on a ride where speed and agility are less important than comfort and endurance, I'd probably go that route. But the compromises it forces me to make on my typical commute mean I'm sticking with the backback, sweaty back and all. Happy to have the panniers and looking forward to using them for shopping trips and other expeditions. But I much prefer the way the bike handles with the load on me.