Remember that you are only training your strongest range of motion, which is usually the fully extended position (lockouts) in the push (presses, benches, etc). With pulls that usually start at a full stretch position (chins, rows, curls,etc). The three ranges of strength for a given muscle are start, middle and finish.Each range has it's own strength level. Trouble with the Power Factor training, only one strength range is worked. Selected power rack pin positions will train all three levels on their own power levels. Example being, some guy's have trouble with the middle range of the BP. That middle range should be trained more for increased power.
Power Factor is a good way to train for short periods (6-8 weeks). The confidence level will rise to the sky. You will get results with using very heavy weights that can amaze other people who may watch you. But as before, it does not always transfer over to regular benching, squats or DL's for example. If you can do a 800lb 4 inch top range squats you will not do 800lb full squats.
With Static holds, do not included with PF'er training as a general rule. Though some very advanced lifters will do a set or 2 of holds of 10 to 20 seconds after a regular workout. Static contractions (another version of the overload system) gives positive results. Many will be surprise that by just holding a weight with those static holds/contractions they can greatly add to the basic power of a lift. Works well with benches and overhead presses. Also very true for squats and the Hise Shrug (the Hise Shrug is another great exercise that no one bothers to do any more...another mass builder forgotten). Paul Anderson set the standard for squats (akin to the 4 minute mile in my view) with static holds and partials back in the 50's & 60's. Other old time strongmen did the same with just standing with a extreme amount of weight supported on their backs, as Anderson did. Can build overall strength.
That Power Factor book has some unbelievable shots of Paul DeMayo, as BigJ noted. Too bad about the smack thing of his. Italian power at it's finest. Matarrazo ran a close second, some good shots of him also. Good Luck.