Summary: I love this lens but boy howdy is it HEAVY. I just sold my Mark III due to its massive bulk, I traded down to a 6D, but when I add this lens I need two hands to navigate it. But...and this is why I bought it, we are talking SHARP.. We are talking FAST.
Summary: I can't explain how much I adore this lens, and how worth the money it was. I own a 13 year old copy that still looks and functions like new. That's really saying something about the build quality of this lens.
Summary: Best lens I have! I have a few prime lenses and this is very sharp. Very heavy but that is not a n issue for me focusing is kind of slow but I use it for portraits so is not an issue. Can't go wrong. V2 is faster but more expensive. Can't go wrong with it.
Summary: This is my favorite Canon lens. It is a pleasure to use and gives outstanding results. It looks like a little Hubble telescope from the front (it gathers light like one too). Its alittle long for group photography unless you have alot of room.
Pros: The best portrait lens in the Canon arsenal. Dreamy bokeh. Very sharp even wide open.
Summary: I bet if you are considering buying the 85mm 1.8 you came across this lens and thought to yourself why is the 85mm 1.2 so much more expensive? Is it sharper? Is it that much better? Not necessarily. This is a specialty lens, and that's one reason I don't own it (I also can't afford it, lol).
Summary: This is a superb lens. Everything good that needed to be said about this lens has been said. Once you've mastered this lens, the priceless photos you'll capture more than justifies its heavy price tag.
Pros: Rock solid L build. Outstanding color, contrast and bokeh.
Cons: Heavy chunk of glass. Slight learning curve. Slow to focus esp. in low light.
Summary: I am not sure what other poster meant by the light issue. At 1.2 the images are a bit soft, but this is a portrait lens primarily and sharpness isnt that important there, can actually detract, at 2.0 it is very useable, sharp, and still has awesome bokeh.
Pros: Very good Bokeh (Amazing Actuall) and stunning minimum DOF