I like dark leads—Pilot Neox 2B is my favorite—but I also like high-quality paper with some toothiness to it.
I’ve found 2B to be utterly incompatible with very nice paper, as the graphite sloughs off too easily and creates streaks and smudges.
Hence, I am keeping HB (Pilot Neox) and weak B (Pentel Ain Stein, Uni Nano Dia) on hand for my finest papers and notebooks.
(Otherwise, I’m 2B or darker on crappy copier paper.)