After all the talk about ABC pyro in the Azo forum I gave it a try. It is indeed a very good developer for contact printing with alt processes and azo. But I think that Pyrocat-HD negs give very comparable results with both Pd/Pt and Azo. Not a super scientific study, simply 2 identically exposed negs, both developers, and subjective evaluation of the “best” print from both negs. The reason I'm usually inclined to go with Pyrocat is that I prefer to use rotary development. The classic ABC developer gave awful streaking and uneven staining when I tried it rotary style. Pyrocat has never given me any streaking with rotary development, something I cannot say even about Rollo Pyro (supposedly specially for rotary). That said, I now do occasionally break out the trays and use ABC for some diversion and added experience with this developer.