Note, they sell the machine cheaply, and they ream you for the bags. For long time storage, yes vacuum packed bags work good. But for backpacking, the bags themselves are very heavy in comparison to even zip-locs. Now they might have made them much lighter than my old ones, but... I wouldn't bet any money on them.
PS. CUT BAGS LONG. That way you can keep reusing them. Every time you seal a bag it uses about 3/4 inch that you have to cut off and throw away when you open it up.