I think it all depends on your commute whether it's a few miles or a lot. I say a backpack if its 4 miles or less. You won't even bust a sweat in the morning depending on where you live. I have two backpacks, a front rack with a porteur style bag, and soon to have a saddle bag. I guess what I'm trying to say is it depends on distance and what all are you carrying into/from work that day to use one or the other.