DonM I built some XDS's for a client. The onset/face progression's are different.
Senior males as they lose distance with shorter playing length mid-irons with jacked up lofts (don't have high enough club head speed with an average playing length 5i 38"/loft 23 - 25 deg. or a 6i of modern variation) as an example) seem perfect candidates to longer playing length traditional lofted frwy woods. You get the traditional loft and trajectory of the club with the longer playing length for lost distance. ie. #9 and #11, etal frwy woods.
Just from my experience.