There is absolutely no rational line of thought which could conclude that a backpack is more quickly accessible than a messenger bag.
The backpack has tons of advantages over the messenger, but quickness of access is not one of them.
Yeah not sure what happened with that response, busy at work. I
MEANT that the mess bag was way more convienent for small items, I use it for quick trips around town. Commuting is done with my Dana Designs rucksack, can't beat it.