Don't have any complaints about this lens. I was considering the f1.2L, but I'm glad I saved my money. The dof at f1.8 is a substantial challenge if you like to work close up... I have no idea how I would handle f1.2.
This is the first time I've had a lens this long, I mostly like wide angle, but its got lots of advantages. I have the 35/1.4L. I bought that lens so I would have an easier time blurring out the background compared to the f2, but its nothing like this. Outdoor photos of family and friends come out beautifully, with excellent OOF areas. Buy this lens and your family may soon try to avoid due to the amount of time you want them to spend in front of this lens. Its a gem.