I do not grow JFK, but I do have John Paul. Here, at least, it is finicky, prone to disease, slow to grow, and a general disappointment. Except for the scent--which is heavenly.

All that being said, I probably have it in a bad location--clay soil and only half day of sun. Plan to move it this year with the hope it will improve. My mother was Polish Catholic, so I'd like to keep it if it straightens up, but there isn't enough yard space to hang on to a poor performer for too much longer.
Sometimes gives decent blooms...
Most often looks like this...