I've been loading the 40 since it was introduced in 1991. I no longer use it, but I formerly used Power Pistol a LOT in 9mm and 40 loads. I finally moved away from PP because it produced a very loud report, quite a bit of flash and a recoil impulse that was half again what most other powders in those same calibers produced.
I used PP primarily with 155 and 165 grain JHP's, not plated bullets. I prefer fast and light bullets, so I never use lead or plated. I pulled up Alliant's load data off their online loading guide, but beware. Alliant lists 9 grains of PP as the maximum load for the 155 grain Gold Dot JHP at 1213fps.
The Gold Dot is not exactly like a regular JHP (they tend to be slicker), but it should be close enough to draw a comparison. I pulled back my starting load to 7.8 grains, and even this load was a blaster. I dropped all the way back to 5.9 grains in order to achieve a velocity of about 1100fps +/-. Even with this load, primers looked OK, but recoil and flash were still a big deal. Ultimately, I settled on #5 and WSF as my favorites for the 9 and the 40 and I cut PP loose.
Power Pistol can be a very useful and versatile powder, that's why I used it for a long time. But, in my experience it was the powder that demanded the most careful attention with actual testing and not just believing what the book says.