Conclusion: Despite its age, that's still an amazing lens. Unfortunately, it lacks the stabilizer and the AF is not up to the best Canon lenses, but other than that, this lens is just great. Distortion is negligible, vignetting is very well controlled and sharpness is very good throughout the whole frame even at f/2. Bokeh is nice even stopping down. Build quality is good and the quite large MF ring is very helpful if you use the lens with a follow focus.
Conclusion: I no longer have this lens, but I really enjoyed it while I did. The quality it produces is really excellent. AF is very quick and responsive and it works great in low light. My only complaint is that the build quality could have been better. When I sold the lens, it must have been dropped or something during shipping because upon arrival the focus ring was jammed (though my shipping box and materials were still perfectly intact) Could have been a fluke scenario, I don't...
Pros: Sharp wide-open, fantastic bokeh, responsive AF, physically a small and compact lens for the focal length.
Summary: I wouldn't give this lens a five star rating. A 7/10, It is a great lens, beautiful bokeh. I do like the option of switching your focusing lenghts. This comes in very handy when you are up close to your subject. Macro makes noise when focusing with AF extremely slow, you sometimes need to MF to get this lens to focus out after working closup with it.
Conclusion: A small, light and inconspicuous lens with very good optics. It is already sharp and contrasty at f/2. Only negative is the rather heavy fringing at high contrast situations. Focus is fast (a little bit faster than the 100L) and accurate. MF ring feels great. Built quality is compact and sufficient. Great (portrait) FL on FF cameras. Cheap.
Pros: IQ wide open, small, light, inconspicuous, cheap, AF