There may be some truth about the canisters not doing as well as the bag, especially if you only have a couple hotdogs in it and a lot of open space. The vacuum-seal is not absolute, otherwise it would probably crush the plastic container, so there "is" some air in that open space.
The moral to that story is, for maximum freshness, FILL those containers as much as possible so there is very little residual air left when you vacuum seal.
Personally I love my canister (of all sizes) and they work well for their intended purposes; flour, coffee, teas, rice, marijuana (just joking), leftovers, etc.