It's not yet available for home use, but when it is, I believe it could replace the vest. If you use it carefully, you can get a lot of benefit from it, although your cheeks, neck, and chest muscles WILL get sore at first.
Because it expands your lungs, I feel like I get an immediate improvement in being able to breathe comfortably. When I was in the hospital a few years ago, my kidneys failed during an exacerbation, so we couldn't continue iv antibiotics. Instead, they offered me a trial of this machine. After four days of ONLY metaneb, my lung function went up 15%!