Not sure I have one. Three iron sets: 1971 Wilson blades, 2006 Ping Raptures, and Alpha C1 Pro irons of unknown date, but probably around the same as the Pings. I hit them all equally good and bad except that left-right dispersion decreases with the game improvement technology (or workability decreases if you are a better player). As far as turf interaction goes I’m not sure it matters to me. The blades feel better on good hits and worse on bad. They also don’t feel as wonderful as I remember from the days of wound balls.
Forgot that I also have Tech Power Forged, which are basically a low budget version of the Alpha players cavity. Actually shot my lowest scores with them.