I have been using one for many, many years and think it has saved me lots of money. I've not lost anything to freezer burn when using the sealer. I also like that the packages are all about the same size and stack easily so I can find things. You can also use the bags for something smaller (think chopped onions) after you've emptied and washed them.
I hit the grocery store early morning when the meat market makes reductions. I remove things like roasts, chicken, bacon, sausage from the store package and repackage it into meal portions. I make several batches of soups, hot dog chili, spagetti sauce and chili and portion that out also. I also figured out I can cook the whole box of spaghetti and freeze portions. When I need it I just take it out of the bag and defrost it in the microwave without any added water. When I do the you pick fruits and veggies in the summer I put them on a cookie sheet and freeze for a couple of hours and then seal them up in a bag. I also spend a day making different types of cookie dough and freeze for when DH wants milk and cookies at night. When I'm tired and don't want to cook there is always something in the freezer to toss in the microwave. The main thing is to write what's in the package on the outside because you won't remember what it was in a couple of months and you can't go on looks! Now that it's only DH and me I do have to make sure to date and rotate what is in the freezer.