Pros: -sharp, sharp, sharp ( between 1.4- 2.8)
-construction is top notch
-bokeh is silky smooth (was never a priority in the past for me, but after seeing the results thats all i think about
-superb in low light situations

Cons: -price, price, price (will not be buying any new lens soon, but maybe i will not have to with this lens)
-attention getter (might be a pro for others)

Other Thoughts: this lens allows you to enter a whole new world of photography, night photography without flash. i have tried both the 24-70L and the 17-55m and felt very limited once the sun starts to set or moving in doors. IQ is stunning, especially the colors. i recommend you rent this lens to try it out yourself.

there are many negative reviews out there about the back focusing issue however i have not really noticed it with my copy. i tried virtually every test to bring about this issue but nothing that was obvious.

in conclusion, i absolutely love this lens( which was hard for me to say about the other two lens). i would love to give this lens 5 eggs but the prices is a bummer

Pros: I use this lens primarily for shots in night clubs. The contrast it produces is beautiful. I am always getting great compliments on my pics. Of course the 1.2 is amazing and combined with my 5D mark II capabilities of low noise high ISO you can take some shots that look like you are there. I used to use the 24-105 f4 L for my night club shots but this lens out performs it greatly. I tried the 85mm 1.2 but didn't like it's longer minimal focal distace and made it hard to get the composition i wanted. This lens is great for it!

Cons: The 1.2 gives such a narrow DOF but this was expected. Not so much a con as a feature I have to get used to. But worth the work for the results it produces. Shooting at 1.2 you can easily get someone out of focus if they are a little off the plane of view of your focus point.

Other Thoughts: This lens finds itself on my camera body more then any of my other lenses. 24-105 f4.0 L, 70-200 f2.8 L IS, 180mm f3.5 L Macro.

Pros: Excellent quality lens. Captures amazing photos with great Bokeh. Super fast and ultra quiet focusing. Very sturdy design.

Cons: None

Other Thoughts: Well worth the money

Pros: Absolutely excellent lens. Ive been a professional photographer for 4 years now and this has been my favorite lens Ive ever used. Ive used the 85mm f/1.2L, 50mm f/1.4, 35 f/1.4L, etc and this lens still by far produces amazing images. The creamy background blur produced by this lens is dream like, and produces tons of "wows" from clients.

Absolutely 100% worth the price.

Cons: IMO its worth the price, I just wish it wasnt so high!

Other Thoughts: If you are considering getting this lens, then get it. If you dont like it there's tons of buyers who will buy it from you at the same price you pad for it. Dont worry about focusing issues you've heard of on forums, etc. It's a problem Ive personally never had in the 2 copies Ive had (I had to sell the first one to raise money for an emergency). It's an issue a few had that has been blown out of proportion.

GET THIS LENS!