Canon SSC glass, FL or FD, is a good alternative to the FD L Series Glass, and it is always helpful, fast glass like the 1.2 85mm L lens, while wonderful, at least the one I had was, especially for fast moving dancers on stage in changing stage lighting, fastest glass can only get you so far, and these SSC lenses are both great lenses, are a real value, monetarily AND Photographically.
FL SSC is also quite good and stopping down manually is no big deal, depending on what you're shooting and the topic shot.
Even the average 1.8 50mm FD lens gives superior rendering, and unless you like cold tonal ranges, is the lens that will best of the two brands, deliver sharp, clear and unique, warm tone images.
This is true through the Canon FD line.
IMO.