I use mine loads, I got an andrew James one off ebay three years ago. The rubber seal on it is starting to perish though, i might get one more year out of it.
Food keeps better in the freezer, homegrown hops, dehydrated foods, fermenting peppers, curing bacon, sous vide, weather seal my phone if going hiking etc etc.
I would agree with drunkula though if all you are going to use it for is grain and hops (unless homegrown, it's essential then imo) then I wouldn't bother