I have done a ton of shooting with Superia 400 and 800, and only think of them as "grainy" when my exposure was very bad. I get rather nice 8x12s from Superia 800, even if it is overexposed by about a stop.
Underexposure leads to the mushy-looking, washed out grain, and overexposure leads to the sharp, gnarly grain.
From looking at that photo I posted, which way do you think I went? I was periodically over-exposing, but didn't take notes.