I play 921 Forged and practice on a launch monitor with a set of Srixon 765. Identical Project X LZ shafts (same weight and profile) and identical clubhead lofts. The shaft feel and performance seems about 95% identical, although in my set of Srixons the shafts feel like they have a touch more kick. It could be my imagination, however. Or it could be something about the slightly different head wight or the different grips. Overall they feel super similar and I go back and forth without any need for adjustment.
I'm about 6 months into this same experiment. Replaced a Mizuno HM set PW with a Vokey 46. Reviewed a bunch of threads on here to get others' experiences doing this and didn't see anything about weight porting the Vokey and I didnt do so (although I did order the 46 with an S300 shaft to match my set). Certainly the Vokey 46 flights several yards lower than my set PW, but that was a part of why I made the change in the first place. Stopping power is the same. Another part of my thinking in making the change was that I usually hit my 58, 54 and 50 with pretty consistent control for line an