Key advantage of backpack: it's free, since presumably you already got one. One can only afford just so many $50 and $100 accessories.
__________________
--
-=- '05 Jamis Nova -=- '04 Fuji Absolute -=- '94 Trek 820 -=- '77 Schwinn Scrambler 36/36 -=-
Friends don't let friends use brifters.