Well, here's my experience with the coating issues. In the mid 70's a friend and fellow photographer, was given his grandfathers mint condition Leica DS M3 with a 50mm f2 collapsible Summicron. I was using a Nikkormat Ft2 with the new multi-coated Nikkor 50mm f2. We decided to see what the differences were between the lenses by loading some Plus-X into our cameras, and shoot the same pictures using a stationary tripod. We really didn't know much about lens design or anything, we were just curious. Though I think the Nikkor was a 6 element design, I'm not sure about the Summicron, but I'm sure someone will know. The results (film dev together and printed 8x10 with the same enlarger) showed some differences on some pics, and none on others. Shooting into the sun or bright scenes showed less contrast with the Summicron, and better contrast with the Nikkor. No lens hoods or filters were used. Including the sun in the frame made these differences more severe. Otherwise, most pics looked the same, with the Summicron showing a little more contrast in a couple of pics. (just the nature of the lens?) So I guess that multi-coating can make a difference in some shots, while not in others. Might be interesting to see the difference between the non-multi-coated Nikkor and the multi-coated one now, though I imagine the differences would probably be about the same.