Chris, I used PMK pyro for a full year with Efke 25 in 35mm, 120 & 4x5 for enlarging. It is similar to Neofin Blau in that it is a staining developer which masks grain and in fact uses similar chemistry. Works very well for enlarging, not as well for contact printing on azo, because the general stain from PMK doesn't reveal detail in shadows cleanly in the thin areas.
I tried ABC pyro for contact printing and had a difficult time with contrast, density and generally fickle behavior, so I stopped using it. I was never able to get consistent results with it, but it certainly is sharp with respect to grain and shadow detail. I know why people use DBI with it now.
I've since settled on Pyrocat with the 1:1:100 dilution for both azo and silver printing for Efke 25. I would have to agree with Ole about a "dual purpose negative" not being the best choice. If you want a contact print on azo, do your film tests first, then re-do them for silver enlarging (unless you go the BTZS route). Make sure to match the paper's scale to the film's contrast, or you will be chasing your own a$$ in circles for a while with mixed results.
This is wonderful film, but it is quirky with respect to development times, temperature, concentrations and agitation cycles. You need to be very consistent for best results and do your homework if you are going to tame it and have it work for you. That having been said, it is great stuff for rendering metallic materials, portraits and a "few" other things. It builds both contrast and density rapidly, so exposure and development are crucial to understainding the limits involved. Still my favorite film in flat lighting or for showing off chrome with bike shots. It is every bit as forgiving as Velvia 50 in E6.
