I have the 50mm 1.4 S.S.C. It is my most-used lens out of all my lenses in any format. Even with some light fungus, it is sharp. Someone wanted to clean it out for $45, but I said forget it! It is sharp as it is, and I don't want someone monkeying with the elements if I like what I am getting.
I have the FDn one as well, just because it came in a kit. I use it as a backup or a loaner. No hood, though.
I also have the 55 f/1.2 S.S.C. with the proper hood. It is one of my favorite lenses aesthetically speaking, as both you and hpulley describe. As you also said, I mount it when "dreamy" or "no-light shooting" are the words.
The 55 does have the most major barrel distortion I have ever seen in a fixed-focal-length lens, though. So I gave up on shooting brick walls with it.
I use the 55 with the Canon low light screen. I think it might be called the F screen (old F-1). Still only seems to show the D of F of about f/2.0, even wide open.