That's also not a messenger bag,it's a shoulder bag. I have one that I use for off the bike. First,the strap doesn't cinch down all the way,and there's no secondary strap,so it moves around(unless you're on a very upright bike like the bikeshare ones). Second,if you get caught in the rain your stuff will get wet. Only the outer flap has a waterproof liner;the rear laptop compartment has no liner,the zipper isn't waterproof,and the fuzzy padding is great at wicking water inside.

It's really disappointing that a company like T2,who make real mess bags,would call this a messenger.