I understand your question may arise from comments that the 35mm Planar is the least-excellent of the G series lenses. I dunno, I haven't made any resolution tests. I think this lens has a really nice character. Might well be sharper than some 35 'crons and not others, as there are various Summicron generations.
I picked a couple of somewhat similar photos to compare, both with the lenses wide open or maybe f/2.4. First one is the Summicron 8-element, second is the 35 Planar, then a 100% crop out of the Planar shot. What do you think?