Power Factor Training

Does anyone have any info on the effectiveness of Power Factor Training? I would like to know if anyone has used it and benefited?

One of the worst piece of investment I have ever had the displeasure of making. I would say it’s next to worthless. (Just like the workout manuals by Leo the scam artist Costa)They come out with all sorts of mathematical formulas to build muscle.

I tried it a few years ago and had some success. However, it’s not the
type of program I’d stay on for long. It relies almost entirely on partial
reps and that can cause problems long term. A nice short term change
of pace, but not something to build your workouts around.