i know that ortlieb and other roll top brands are completely waterproof, i already have a roll top bag. i just love my midpack for all the reasons i hate my roll top. i can beat the crap out of it and not worry about it falling apart and fill it to the brim and still ride it home comfortably. i fit 24 bottles of beer in it and walked home, that would KILL in any of my other bags and until recently, it was completely rainproof as well. the only thing besides the leak that i don't like about it are some customizations that i've only thought of since i got it...i'll get them on the next one.