I had a SMC 55 briefly, it was a gift to brother in law, but I had to test out the camera after all
I liked it so much that later I bought an Auto-Tak 55/1.8 for $10, even though I already have two 50/1.4s (between the varations, you can always tell yourself you're sampling the flavors)
Here's another line up of the bunch:
Click on the image to view it in a larger size
I did a bokeh test once, the 50's are 2 and 3, the 55 is #4.
Click on the image to view it in a larger size
Click on the image to view it in a larger size
I also did a CA/flare torture test, in which the 55 outperformed the two 50's, and was close to the 43. Which is the main reason I wanted another copy for myself. The FOV difference isn't all that much, you do notice it but soon get used to either.
Here is the brother in law's 55, on a Spottie:
Click on the image to view it in a larger size
and here's an impressionistic 50 also on a Spottie:
Click on the image to view it in a larger size