few advantages beyond somewhat increased storage life.
Hmmm. My thought is to use dried and dehydrated food anyway, so the increased storage life might not be as much an issue for me.
My preference is to just use a heat sealer and the much lighter and just as robust (and much cheaper) sandwich bags.
This sounds like a vote for the really cheap use-a-straw-to-suck-the-air-out-of-a-freezer-bag method.
Another pro for the vacuum and freezer bags over sandwich bags is for freezer bag cooking. I suspect (haven't actually tested) regular sandwich bags would not be as robust when confronted with hot water for re-hydrating.
Thanks to you both for the input. I now have to decide between another gadget in the kitchen or a titanium straw. Either way its good.