We have and regularly use our vaccuum sealer (a foodsaver). We love it and yes it helps keep it fresher longer. It has been used with the mason jars to keep ground coffee fresh. I usually grind fresh every 2 days or so but when my father in law visits, he drinks this 1/2 caf or decaf stuff. Rather than throw out the unused portion, we seal it. It stays remarkably fresh.

Meats stay longer in the freezer and don't get freezer burn.