I've just tried a roll of Delta 100, developed in Paterson FX39 for 11 min at 20 deg. It really is EI 100 (well, 107), CI=0.78. The curve doesn't have such a pronounced "toe" as T-Max 400, the slope doesn't flatten much, so the shoadow detail is well defined.(posted 9892 days ago)And it's sharp. With good lenses, I get 52 line pairs per mm (TMY gives 37).
Grain, what grain? Well, yes, there is some, but it's nice and sharp, which I like. (I used to find Tri-X grain soft, which I didn't like. HP5+ had sharp grain.)
You may find that Kodak T-Max 100 (TMX) is similar to Delta 100, as T-Max 400 (TMY) is similar to Delta 400. Both use a newer image structure than HP5+ and Tri-X, giving much finer grain.