I have had great success with the 9.5 head as a matter of fact it keeps pace or better with the M5. It’s a low flying missile and I normally play a bit more loft so I grabbed a 10.5 when an online forum member immediately sold his 10.5 head as he struggled with it.
I shafted it with a shaft that worked in the 9.5 head but really struggle to get the 10.5 to work. It has to be hit perfect to go and even then its blah.. Conversely the 9.5 plays well on less that perfect contact. A full bucket of balls and I couldnt get comfortable with it and I can hit just about anything.
I know you switched foundaries and are reworking dies. Had you seen variances in tested club heads. I’m baffled by the difference in performance. I have also seen some of the mixed reviews that have been posted.