Barry Thornton in The Edge of Darkness raves about Perceptol 1+3, it does give high acutance and fine grain. It's a good combination brilliant with FP4.

But I have to say that the APX100 / Rodinal combination produces some of the finest grain 35mm images I've seen with superb tonality, this is because the two are designed for each other by Agfa.

Crawley makes a point of saying certain Ilford developers give outstanding results with Ilford films but weren't as good with some Kodak films. Ron Mowrey (PE) has said much the same in this thread Or the other half) in a slightly different way.

Manufacturers tweak films & developers to match their products.