Colistin is great, at least it has been for me. Everyone's going to be different, of course, but this drug has really turned me around and restored lung function I thought I had lost for good. Basically I had tried a ton of different IV drugs over the past few years, but nothing was making me better for any extended period of time... finally I said to my doc, fine, I'll try Colistin again (I had not taken it for years because the first time I took it, it had no effect)... and the results have been fantastic.
The only bad thing about it is the fact it is fizzy and sticky (also you have to mix it up yourself, but I don't see that as being too bad). I've tried everything possible to keep it from fizzing in the neb but have yet to find anything that works.
Aersolized colistin also has the added bonus of being very difficult to become resistant to - that's why a lot of docs like to put patients on it for extended periods of time.
Hope it works for you, let us know how it goes.