I am not going to go so far as to say that Messenger Bags 'suck', but they are not for me. In the summer months I am frequently riding home in temperatures in excess of 100 degrees. The last thing I want is something hanging against me holding in more heat. I never found any kind of bag I liked until I got a rear rack and attached a bag to it. For me it doesn't really matter what it is, just so long as it isn't hanging off of me.