IIRC, Wolff used to offer two different "Power Rib" replacement MS's for S&W revolvers in the Brownell's catalog: one rated at the same level as the OEM and one reduced power "Competition" unit.
As my most-used S&W at present is my 625-4 in .45 ACP, I chose the factory-spec Wolff when I decided to start fiddling with it. This was primarily because of anecdotal info that some folks had experienced a significant number of ignition problems with some brands of .45 ACP ammo and/or primers using the reduced power unit.
As I said, the info was purely anecdotal and I have no direct knowledge on how prevalent or severe this "problem" might actually be. What I can say from experience is that I've had absolutely "zilch" ignition trouble from my revolver using the factory power Wolff MS no matter what ammo I've used so far. And IMO the action "feel" showed a slight, but noticable, improvement with it. The DA trigger action just seems to be smoother and more "fluid" than it did with the OEM spring to me.
Entirely subjective opinion, of course, and YMMV. IMO, I've spent more than that $16 and gotten less for the money elsewhere before.
