Originally Posted by
SkyDog75
And it can obstruct your view when you turn your head to look over your shoulder, which is necessary to ride safely in traffic.
On the other hand, panniers are attached to the bike when you ride. You're not carrying any weight on your shoulders or torso. You're not going to get a sweaty back. Mobility and sight are unimpeded. When you get off the bike, just take the pannier with you.
You must have a huge non-contoured backpack to impede view.
Also, those Ortlieb panniers are excellent as a pannier and ****ty as a backpack (no comfort). I'll admit that they're extremely durable (usually about 10 years of usage before wearing through) but like most things German, lacking in comfort.