Full review will be coming in the next few weeks. These compares right now are quick analysis I use and compare the two lenses. Please see Compare #1, Compare #2 and Compare #3 posted earlier.
So, I decided to throw the 1955 Summicron 2/50 Collapsable into the mix. Muhahaha! For this first test, the three were shot at their respective wide-openness from relatively the same vantage point (I was too low to use a tripod). Above is the modern f/1.5 Zeiss Sonnar. Below find the modern f/1.4 Summilux-M ASPH and 1955 f/2 Summicron versions. Nothing scientific here - just a bunch of SOOC files to look at. Click for large:
I also took these to the swamp for some f/11 compares. Again, all RAW, all SOOC. I kept the shutters identical (a little on the dark side, though):
Finally, a compare of just the modern glass - settings ISO 160 f/2: