Sure a summicron is a good lens. It should be for the money you pay for it. I just don't think the majority of photographers out there would be able to tell the difference between a print from a summicron and a smc tak. There are probably more photogs here who could tell the difference, but I doubt many could tell which one is which. I read an interesting test where the same shot was taken with four different lenses (Med format)on the same film, same soup, same subject. Guess which one John Q Public chose as the best lens? The Mamiya! I believe they compared Zeiss Planar, Mamiya Sekor, Bronica Zenzanon, Schneider Kreuznach Xenotar. With another subject and lighting, one of the other lenses would probably get the nod.
I have a Color-Heliar 105/3.5 that has "cult" status because of its "glow" at wide aperatures. That glow (ever hear of the leica glow?) is lens aberrations. They go away when you stop the lens down. At f11, you or I will not be able to tell the difference between the Heliar, Planar, Xenotar. (I have all three). I'm talking about picking out an 8X10 print.
My point is not to denigrate any top quality lenses at all. Are there differences in micro-contrast? Sure. Resolution? sure. tonality? yup. You will probably find differences in each of these areas between identical lenses made in different years too. I have a 50/4 Zeiss Flektogon, arguably one of the finest wide angle medium format lenses anywhere, and it's a piece of crap. If doesn't get sharp in the corners until f11. I just got a dud.
Get out there and shoot what ya got.