Re: Hi-Speed Firing Pin
I have, and do use HS strikers in several of my rifles, and I think the do help a bit. Problem here is, I'm a competitive shooter, and I think it's most useful advantage comes in offhand shooting first, and sitting second. From a solid prone with a sling, I don't think I'd really see any noticeable difference. Ditto for a solid rested position, as I assume you're asking about a hunting rifle? I've installed them in both rem 700s and Win 70s, no problems at all in either one.
I also use a lightened hammer in my Service Rifles (ARs), but again, we fire 25% of our score in offhand and that's a worthwhile advantage.
Bottom line is, they get the bullet out of the bore a bit quicker which is always a good thing, but more critical in those positions which good follow through is the most difficult. Up to you . . .