The shaft, not the head, drives performance
Comparing the same iron head with two different shafts on a launch monitor, the fitter shows how much the shaft alone changes performance: about 18 yards less carry, 10 mph less ball speed, and a smash factor of 1.31 versus 1.4 just from swapping shafts. Takeaway: the shaft is critical to performance, so get fit for the shaft, not only the head.
Channel: Club Champion
Watch official source at 27:49Why this context matters
After A/B testing the same head with two shafts on TrackMan.