The other developers you listed are all solvent developers. PMK Pyro (and Pyro developers in general) is an acutance developer. It will give you sharp negatives with more grain as a tradeoff. It is a staining developer. Depending on the film, it will give the negatives a greenish stain which is proportional to the silver density. When printing, the stain increases the effective printing density. This means that the printing density in the negative is the sum of metallic silver density and stain density. Because of this, the silver density can be lower than in conventionally developed negatives. This is an important point. It means that compared to what you are used to seeing in a normally developed negative, a negative developed properly in PMK will appear lower in contrast to your eye. So, particularly when starting out with Pyro, it is important to print your negatives in order to evaluate whether they have been exposed and developed properly. It is hard to judge the negatives by eye.
The lower silver density, combined with the stain, helps reduce graininess to some degree - although people tend to overstate this effect.
PMK is a little more tolerant than early conventional Pyro formulas, but still needs carefull attention in processing to avoid streaking and uneven development. Proper agitation is critical.
To maximize proportional stain ("imagewise stain"), it is generally best to keep the process neutral or alkaline in pH. Use a water stop bath procedure rather than the usual acid stop bath. It is debatable whether or not it is necessary to use a neutral/alkaline fixer rather than a standard acidic rapid fixer, but the conventional wisdom is not to use an acidic fixer. You do not need to put the negatives back in the used developer as is sometimes recommended. Wash with water as usual - don't use a hypo clearing agent.
These are just some basics but hope it helps.