My Rachel tried it out for three weeks last spring. She loved it. Rachel had about a 5% increase in her pft's after just three weeks. She felt a noticeable difference in being able to get junk up and out. She's always had difficulty getting it up and out.
We first came across it in late spring 07 while at Lucille Packard (Stanford), CA., waiting for Anna's transplant. It had recently been approved by the FDA then. I think they were one of the first CF clinics to have one.
We have been trying to get one since Nov.08. Not much luck but we are still trying. Just re-started the process today.