I play to a 12 hcp. I've played Adams, Callaway, Ping and Acer GI irons all to a 12. I also play to a 12 with my Wishon 555 and SMT 303 MB blades. As I've gotten older I've replaced 3, 4 and now 5 irons with hybrids but still view my 6-PW blades as "scoring irons" (170 yards in)
Believe it or not the trouble I had with GI irons was distance control. When I pured one the ball travelled a good 20 yards past the target. If I miss with my blades I might come up 5 yards short. Most courses I play long over the green is dead or OB. A little short is never much of a problem and when it is I club up just in case.
Seems pretty obvious to me that the 12 hcp is what happens inside my head and not influenced much by the design of my irons