Keep watching, there are a lot of these lenses out there and another one will come around soon.
I've owned several examples of them. They tend to be characterized by moderate contrast (at best) and like a lot of older high-speed lenses, the image structure at wide apertures consists of a fairly sharp central core surrounded by a haze of blur. Back in the film era we usually dismissed this kind of performance as "mushy," but now digital shooters seem to enthuse about this "drawing quality." (And it's worth noticing that unsharp masking usually cleans up this kind of mushiness well when required.)
One thing worth watching about this lens is that it's very susceptible to flare from light sources near the picture area, so a lens hood is very helpful. Canon made an impressive-looking vented hood specifically for this optic, but don't be surprised if it costs almost as much as the lens! Another quirk: the front element is unusually convex, to the point that some standard filters will rub against it when screwed in; check before installing. Again, Canon made special filters with the glass mounted flush to the front of the rim.
A shocker is that Canon's 50/0.95 lens is sharper than the 50/1.2 at every aperture -- but the 0.95 will need an expensive mount conversion to use it on any camera except the Canon 7/7s, whereas the 50/1.2 will fit on any LTM camera, or any M camera with an adapter.