Bruce, it does not soak in and go to completion the way a two-bath developer does. It works by time, temperature and agitation the way general purpose developers do. So it is just as important to work out your own film speed and development time with PMK as it is with XTOL, D-76 etc. The difference is that the image density is composed of silver plus dye ("stain"). So it can be difficult to judge the printing contrast of the negative without printing it.
The reason some people don't like PMK with small negatives is because Pyro negatives are indeed grainier than negatives developed in a general purpose solvent developer such as XTOL, D-76 etc. The grain masking effect of the dye helps slightly.