I have commuted with a backpack and hated it, if you don't already ride with a backpack I would try it on a ride of 5-6 miles with a change of clothes and a lunch and laptop if you carry one. I found the straps dug in under my arms and cut off the circulation to my hands and my hands would go numb after a little while. I tried a better pack with a chest strap to keep the straps more centered and it was a little better. I then switched to a messenger bag and really like it a lot better, I still get a sweaty back to some degree but no circulation issues. Keep in mind this is my experience, some people really like using a pack. I think a pack is easier if you in a more upright position as well... Just something to think about before dropping a ton of money on an Ortlieb..