Dave Karp is right in his observation that Barry's revised formula called for Metol 6.5 grams instead of 6.25 grams. I had dialogued with Barry on a regular basis for about 3 1/2 years prior to his untimely death. In fact, we were talking about planning some time together doing some photography in the UK. Photography really lost a master photographer and passionate teacher to all.
I have developed many hundreds of rolls of film with the Barry Thornton 2-Bath developer over the years, and have found it particularly useful for roll film processing. (IDEAL FOR: many images with variances in exposure or contrast scenes, or processing in one large tank several different film types are made easy with the 2-Bath process).
While most of my work is now done with sheet film—pyro and brush development by inspection method, I find Thornton's formula hard to beat particularly for anyone not requiring (or desiring) a tanning and staining developer. If one desires a little added sharpness without inducing grain, one can add 6-9 grams of sodium ascorbate (vitamin-C buffered) to bath A and develop as usual with little change in contrast. But, in reality this developer is just so nicely balanced that tweaking it too much defeats its purpose in my way of thinking. Simplicity is such an important key in the quality and elegance of a good developer. Simplicity of formulation also allows one to learn more easily the behavioral characteristics and cause relationships (influences) between developing agents and constituents. While I like the use of sodium metaborate because of its balance with contrast and grain combination, one can use borax for finer grain or sodium carbonate for increased sharpness. But for all intent and purposes, all images will work very well with sodium metaborate as the activator in bath B.