customwork, there is a difference in the COR (CT) in various thinner faced iron designs. We can measure this on any iron. It is however quite minor and effects the playability of an iron very little. It is not even close to the large headed drivers. An iron would need a different material in the face to increase CT, but it will still be very minor to drivers using special titaniums and heat treating because of its size and the concentrated mass it requires in such a small area. It does make good advertising copy however and it is a true statement as long as you do not go overboard on the benefits.
Keyser, you may be correct that a very high CT iron (if it was possible) may be harder to control for distance. I don’t know this as a fact but it is an interesting conversation.
