I haven't used the zip vac but do use a vacuum sealer for fish and game.
The Zip Vac seems like a concept that the zip lock people came up with to expand their product offering. The zip vac bags are expensive (more than $1 each I believe) and to get full value you need to re-use the bags. Washing fish slime or blood out of a bag and then trying to dry it so that it can be used for the next time is not something I would want to do. Without sterilizing it I would also be concerned about bacteria........
It will cost you more to get a vacuum sealer, but the bags are less expensive and because of that you probably won't re-use them.
Any product that takes the air out of the packaging before you put it in the deep freeze will "let you savor the flavor months longer".