Ive used my ortlieb roller plus a couple years now. I find they work pretty well. They have decent shoulder straps for dragging around, but I love them on the bike. I can carry a lot of stuff in them and I dont find they hinder my ride too much. I backpack is terrible in my experience, even for shorter commutes. Ive never had problems with them getting grime from the road as I use fenders for the rainy weather. I really like the look of the arkel bug, and may pick one of those up sometime in the future--looks like the best of both worlds. The problem is that I just love the attachment system of the ortliebs--cant be beat IMO