I just posted this on another forum, and though it might be helpful to you all.
There are basically two types of vacuum sealers, here is a good video that compares the features:
EXTERNAL VACUUM TYPE: Examples are the Food Saver, Weston, etc.
This type of sealer sucks the air directly out of the bag, stops the vacuum, and then seals the bag. Because of the way it works, it requires specially designed vacuum bags. Because it is sucking the air directly out of the bag, the juices tend to be sucked up into the seal area as well.
* Lower initial cost for the machine.
* Smaller footprint, easier to store.
* Bag size only limited by sealer width.
* Bags far more expensive. These machines need a special bag with a waffle type pattern embossed in the bag to be able to work properly. Those bags are much more costly.
* Not good for vacuuming liquids or wet product.
* Typically not designed for continuous use.
VACUUM CHAMBER TYPE: In this type, you place the bag inside a chamber and the entire chamber vacuums down, the sealer triggers, and a couple seconds later.
* This is what is used by businesses who do vacuum sealing for a living.
* Higher vacuum can be achieved.
* You can vacuum seal liquids like soups.
* Since the whole vacuum chamber is being evacuated, liquid is not being sucked up into the seal, which is the main reason seals fail.
* Far more reliable seals. Very few bags leak which can lead to ruined/freezer burned food. Damaged food means lost money.
* The bags used for this are a more typical type plastic bag, so bags are FAR cheaper, typically a 1/10th of the price of the other type. Because of the low cost of the bags, we often use ours to repackage things like extra food and leftovers. You can also buy bulk meats, repackage and save $.
* You can typically use heavier plastic bags, like 4 mil bags. Some even seal retort type bags.
* Longer life, commercial grade units. The most reliable are those with an oil bathed vacuum pump.
* Designed for continuous use.
* Vacuuming cycle can be customized on many units (like on the VacMaster VP215)
* Higher upfront cost for the machine
* Larger footprint
* Bag size limited to what fits in the chamber.
We personally went with the VacMaster VP215. After a few years of use, the bags themselves will pay to difference of the machine. After using this chamber type sealer (oil bathed vacuum pump), I would never switch back. We keep it set-up in our pantry and vacuum seal things all the time. It is quick, cheap to use and reliable. If you do get the external vacuum type, save some heart ache and get something quality like a Weston.
Remember, after a few hundred bags, the difference in bag price, bags thrown away due to bad seals, and lost/damaged/freezer burned food (due to bad seals) will pay the difference between the lower priced and higher priced machines.