None of the above. I use 10%, and have posted on this topic before. I found myself getting used to 7%, and not being as productive. I emailed the principle investigator of the UNC study, and asked how and why 7% was chosen, and if it was reasonable to move up to 10%. Bottom line, 7% was a compromise of what was effective and what was tolerated, but for those who can tolerate it, the higher concentration does work better.
Chris
27 m w/CF
Chris
27 m w/CF