I have lots of 35mm Tri-X negatives, processed in Pyrocat-HD, and they are very sharp indeed. Grain is about on par with Rodinal, which means it's relatively fine grain, but what appeals to me is the visual impact of the contrast that the stain yields. Super sharp and high acutance. Beautiful stuff to work with.
I also remember it working exceedingly well with Ilford FP4+, which I used in both medium format and 35mm, and those negatives print like a dream to 12x16 or 16x20.