With Polymax in VersaPrint you can get deep blacks in 2-1/2 minutes at 1:1:4 dilution. The "4" is the water. Less dilution gets more speed.
Yesterday I contact printed a negative as best as I could match it, and it came out pretty close, on Polymax in VersaPrint, at Grade 3, and on Azo Grade 3, in amidol. The Azo print is colder, with the Polymax showing some warmth, which is obvious with the prints side by side. To me, both tones are lovely. Fine detail is noticably sharper on the Azo print. The Azo print offers more clarity. But the difference with these prints is not startlingly different. They both have desireable qualities.
I seem to be able to print successfully almost any negative on the Polymax. Azo requires, I think, a different set of skills. I can print some negatives easily on Azo. While another negative, which proofs very similar, I find now impossible to print on Azo. I think I just have to learn how. It is the few really nice Azo prints that motivate me to keep trying.