In addition to the developer you're referring to, which was created by Pat Gainer, I've been experimenting with vit-c in other developers. One interesting observation I've made is images developed with vit-c developers seem to have a brightness about them that I find very appealing. And this occurs without harshness. I've never measured it, but it looks like the H&D curve rises slightly in the zone VI to zone VIII region. Another thing I really like is the images are very sharp, but the grain is smooth and not at all prominent.(posted 8107 days ago)I can't tell you how it might compare to XTOL or HC-110, since I have not used either of those developers for some time. Nor can I say how it would work with FP4+ or TMY. I can certainly recommend it for TMX, Acros and Delta 400 (new). I've used it with tanks and tray and find it very clean working, even developing and consistent. Also, mixed as I originally recommened--divided A & B--it lasts quite a long time. I've seen no deterioration in my stock solution's performance over a 6 month period. It's also very simple and cheap to make.
Gainer's formula is one of the best developers available and I highly recommend it.