Well, I owned the 85L II for about 2.5 years and I loved the lens. It's a very good one.
When I first got it I was still in my 'Holy Crap! Shallow DOF is so cool!" phase and so I shot it wide open. After a year I finally got over that.
Once I started thinking a little bit about DOF, blur and composition I naturally started stopping down more when framing tighter. And so I found myself rarely using the 85L and 135L wide open because I typically used these longer focal lengths when framing more tightly.
So for me, the 85L was redundant with the 70-200/2.8.
If you are the kind of person that likes to use very long working distances (like more than 20 feet from the subject) while maintaining a very strong background blur, then the 85L is a killer tool for this.
But you gotta be careful to not walk to 'normal' portrait range of 12-15 feet, frame up a tight 85mm f/1.2 shot and think you will have enough DOF. You won't.
And while a lot of photographers will excuse totally smeared noses and ears because we lust for thin DOF, a lot of paying clients won't like it. I've heard (believe me, I've heard!) that some of my friends and relatives are not keen on this look.