a mobile vest vs a motor run vest

Hi community,
My doctor's office ordered me a Hill Rom vest, which has a motor. I have been using it for a few days now, but I don't see the obvious result from using it. It doesn't bring up more mucus for me.

My question is do you have a preference with a mobile vest and a motor run vest?I am thinking that having a mobile one would be more convenient, just don't know how good it works.
Thanks for your input!
Ling