Well, smelling fresh of fixer, I just emerged from the darkroom doing a couple of prints from 35mm, 6x7, and 4x5 (yes, long, cold night in the shed) and I couldn't see any perceptible quality difference in the print between and of the brands. I have a 50mm 2.8 El-nikkor, 105 Componon-s, and a 150 El nikkor. All are perfect as far as I can tell.

By the way, I did an enlargement of a 35mm neg shot with the Nikon E series 50mm 1.8 on Fuji Acros developed in Pyrocat and am convinced it could go to 16x20 easily. Brilliant little lens/film/developer combo.