I just got the Percussor 5000 to try
I talked to Sharon (she's awesome)at Customer Service and she sent a demo to my primary doctor's office. (I only go to my cf center once every 2 months, and it is an hour away).
So far, I'm not very crazy about it. I can only tolerate it at a slow percussion and very low speed. Trying to use it on yourself is not the easiest either--especially on the back.
I also need to brush up on the drainage positions because I have not done them in 15 years.
All in all, it might be a good tool to reach areas the vest doesn't seem to do well, or to give extra attention to a problem area. For me though, I like the vest a whole lot better.