I hear ya on the pass through zipper concern. That is my biggest/only concern with the pack as well. I have a feeling that for the first few trips I'll be a bit paranoid and will be checking the bottom pretty often to make sure I'm not getting any zipper movement to expose the contents to potentially falling out. Or I'll go the route you mentioned of just zip tying the bottom zippers together to eliminate that concern. Personally I could do without those zippers all together. I like the top zips though, mainly because I like the idea of running something like a rifle inside the pack and leaving the top zips open to allow the barrel to run out the top. But I could live without the bottom ones for sure. Oh well, it's a minor issue for me and one that is easily resolved with a zip tie.