I've been through two 4 gallon cases of it now. I simply refuse to use anything else as long as I can get it. It's very quirky developer, but the results are unique. One must believe Fred DeVan's admonitions about agitation and take them to heart. That's how you tame contrast with Harvey's 777.
It seems to lose significant potency after 6 months of use, so I dump half of my ripened gallon and fill the jug to the top at that time with freshly mixed developer. I use the rest of the new stock as replenisher.
I'm not actually using it the way Cartier-Bresson and Gene Smith and Fred DeVan did. They used 4 gallon deep tanks. I use 1 gallon in a tray.
I develop 400TMax in it by time and temperature and Efke R50 by inspection. If I could see anything under the inspection light with TMax I would do that by inspection too.
Take a look at the
3rd picture from the left on this page (thumbnails at the bottom). The one of the child turning the corner taken in Greece. That's the look you get with it. There's no doubt in my mind that 777 was the developer used for this picture. (The appearance of blown highlights is due solely to poor scanning. I've seen this picture in books and it's beautiful.)
HTH
Jim Shanesy