I develop 4X5 and 8X10 negatives with ABC pyro. I tray develop by inspection (with green lensed safelight) in the same manner that Edward Weston among others did. I have found that the negatives developed with this developer have better tonality then those which I developed with other developers such as HC110. I purchase my chemicals in the individual componants and mix these myself. Pyro should be handled with precautions it is easily absorbed through both the skin and the lungs. I wear a respirator when mixing it and I always wear latex gloves when developing. I would imagine that the PMK variation would better serve the needs of the roll film user. ABC does not exhibit the strong overall stain that PMK does unless the Bisulfite gets some age to it. The overall stain can actually reduce the contrast range on the negative. I have not found the grain to be a problem...in fact some have stated that the stain will actually mask grain. I hope that this is some help to you in your considerations. Good luck and have fun.