in me expeirence they both leave your back sweaty and to be honest i can carry my XL seagull with a 30 pack of beer for a 5 mile ride or load it with my daily gear for to and from work commuting 20miles round trip and dont find it any less comforatable then a backpack. if your going to go with a company like seagull customize it to your needs. cycling already saves money so spend a little on making the transport or various articles comfy. mine has a padded back, lock holster on outside, cell phone pouch ( from freight) polo mallet holder, and other various add ons that seagull allows you to do. I cant say that its more comfortable or less then that of a back pack as i havent used a back pack for over 3 years...personal opinion honestly. if you got a friend with a spare messenger bum it off em for a week or two see how it feels if dropping money on it and not knowing how you like it is. critique what you do and dont like about the bag borrowed and go with a company that aims to improve on the cons of said sample bag without compromising the pros of the tested bag.


Oh and TJSPIEL have you thought about using a messenger bag that slings over the uninjured shoulder?...most companies will make bags left/right shoulders...just looking for input as I have recently been looking into buying a new mess bag that slings over the opposite shoulder then my current just to even the wear as I am looking long term to commute via bike.