hi cabgodfrey...my 18 yr old g551d daughter has been on for about 60 days. Prior to starting kalydeco, her function dropped from the 70's to the 40s over the course of about 2 years. She has less coughing now, claims to not feel any differently, and I am anxiously awaiting her second PFTs. Her FEV1 returned to 2.2 from 1.8 a month before that. Her response to the drug seems quite tame compared to the stories I have heard, but improvement is improvement, and I will happily take whatever she gets. I am anxious for news on her regarding whether or not she can stop taking Cayston, because I want it to work when she needs it to work. I understand she still will get exacerbations and I don't want to build resistance, the way she did with TOBI. Good luck...I hear there are some modifications being made today by Vertex in regards to the outcome of some phase 2 trials of 770/809