Nicholas -- Last night's prints at f/8 were hideous. It has been a long time, but I'm sure I've had good results at f/8 in the past with this lens on other enlargers, so I suppose that does rule out diffraction. I shot Tri-X and stand developed for an hour in 1+100 Rodinal, so the grain is very apparent. My concern over what I saw through the grain focuser came because at f/2.8 and f/4 the grain had sharp edges, but the farther I stopped down, the softer its edges became and the blobbier it looked. I suppose this could just be because it was darker and I couldn't see as well.

Ralph -- Thanks for boosting my confidence in the lens! I did choose it for the glowing reviews I've read of it, and, though it's been a while since I used it last, I'm sure it was giving excellent results at f/8. As for fixing the enlarger column to the wall -- well, I'm not sure how my mom will feel about that...