I ride with one Ortlieb pannier every day to work, 10 mi round trip. It's moderately loaded, maybe 10 pounds. it works just fine and i've gotten totally used to it. I don't want to corner sharply like on my road bike, but you don't need to do that on a commuter anyway. It actually only feels weird on the weekends, when i ride my road bike without the ortileb pannier. it's like i have trained myself to ride with it there and it only feels different getting used to it not being there! funny!