Not sure if this story needs to be told, but here it is....
A few months ago my beloved TS2's began to fail me. They had been as reliable as any iron I ever had for several years, in the past few months i realized I rarely hit the 5i well, then the 6i , and soon the 7i followed. They just felt "off". So it was time for a change. I had built a few test clubs a few months ago (TS3, TS4, TE+), and the clear winner was the TS4 on a KK graphite shaft. I decided to take the plunge and built a set of TS4 on the Swing Science 200 (same specs as the KK less $). And for 3-4 rounds they were money. Interestingly the graphite did not give me a boost in yardage (even when corrected for diff lofts), they were if anything shorter than I expected. But they were straight and high and looked cool. Then the balloon popped. In one round I lost my swing. Range time, a few more rounds, and it only got worse. I lost the feel. I was hitting it all over the place, all over the face. During one round I picked up my buddy's steel shafted iron and it felt so much better - heavier, and i could feel it on plane.
So I did what any buzzer would do and promptly reshafted my irons with steel (D4-5, with TT Score, +3/4"). It is only a few range sessions and one round on a par 3, but WOW! Not only has my ball striking improved, but I hit these further and higher. I flew my 9i 135 easily, I hit my GW 115 and it stopped on a dime.
On another note, i put on the Lamkin UTX cord grips. I've never used cord before and these are great. Softer than other cords, but still very cord-y. On sale for $8/grip now