Staining developers are really in their own category. I use a lot of PMK, but not for every kind of film. I like it better than Pyrocat, although they are similar. They are based on different kinds of "pyro" (pyrocatechol versus pyrogallol). The image stain color comes out a little different.
I did notice a dicey statement in relation to how far film can be "pushed" in different kinds of developers. That's a loaded question, first, because different films differ in that respect, sometimes greatly; and second, because the terminology of pushing itself is less than ideal, is frequently ambiguous, and can mean different things to different people. A third factor is how the degree of developer dilution or not factors into this. A developer like HC-110 can be made to work over a remarkably long range of dilutions, depending on what kind of curve structure you're after, while some other developers have a rather restricted range of usable dilution.
HC-110 was developed mainly for sake of big pro labs; but the poor man's (or budget-oriented lab's) substitute was DK-50. One advantage of traditional syrup style HC-110 was the tremendous useable lifespan of the undiluted concentrate itself.
The disadvantage of D76 is that you either need to standardize on it freshly mixed, or allow about a week for it to pH stabilize after mixing, because there is an initial shift.
