I am 73 years old ,currently 12 h with 75+ iron club head speed. My current 7i is TaylorMade m4 with Fujikura Atmos 6r flex. When i make a good swing ball fight is high trajectory, that I like. I looked at shafts from the low $ end to the high $ end and not understanding what makes the higher end shaft better than a lower. I do struggle with my m2 driver as am trying to change an over the top swing plane and open face that creates my slice. When I started the game of golf at 60 years old and made the biggest mistake of not taking lessons when I started playing golf. Now working on the damage caused by no lessons. I do have the foresight gc2 with htm golf simulator that helps a lot when practicing. I would to spend the money on different shafts to find what works best and than build from there.
I have a TaylorMade burner 24* with the TaylorMade burner super fast re ax 60 r flex that I had from the beginning of golf and is go to club as verry consistent with hitting a draw.
A newer club that I have is Ke4 19* with Tensei ck 80 hy r flex and is performing verry well.