The American test kitchen show did a special on vacuum sealers.
What they found out was that the cheap bags were actually punchered by ice crystals and let the air right through.
Then they took thicker bags that the ice crystals didn't makes holes in and found out that many (not all) of the cheaper sealers could effectively seal them.
On the sealer side of the equation was the more vacuum removed more air by compacting the meat - so higher vacuum is good as well.
Regards,
Spot
