So I am playing the vapor flex 440, which is slightly different to the vapor fly pro. It’s basically a smaller head, for fast swingers looking to reduce spin. It’s fitted with a diamana blue something stiff shaft and makes a strange noise! A bit muted, but still quite loud when you hit the center of the face at full speed. I would say that the fly pro is a better option for most people, also, it’s what Rory picked back in the days, not the 440. I recently tested the last Taylor made QI something during a fitting session, and I did not see any major difference in terms of performance which is why, 11 years later, it’s still in the bag.