I first tried Power Pistol about six years ago, after reading Iowegan's writings on it. I use it for 9mm and .45 ACP. For 9mm, I use it with 124gr TMJ Xtreme bullets to duplicate Federal Tactical 124gr JHP rounds for practice. For .45, I use it with 230gr TMJ Xtreme bullets to duplicate 830-850 fps GI hardball for shooting in my 1911A1. For .38 Special, I've found that CFE-Pistol provides higher standard pressure velocities with 158gr cast SWC bullets than Power Pistol does. P-P is still a decent powder for .38 Spl loading, though.
As a side note: 30 years ago, Herco was my go-to powder for higher velocities in .45 ACP and .38 Spl. I did use Herco for 9mm, until I found AA#7. Now, I prefer Power Pistol and CFE-Pistol for most of my 38/45/9 loadings. W231 still gets used for lower velocity handgun loads, but not as much these days.