I have had 3 copies of the 24 L II and I was very impressed with the feel of the lens and except the lens hood, very nice build quality. But that's it. I didn't like it at all IQ wise and AF was absolutely useless.
May I ask what you did not like about the IQ of the 24 L II?
Yes you may! Mine wasn't very sharp, both because of AF issues and I didn't have a great copy, it had annoying CA. The things I liked about it was the 1.4 of course, superb color and good contrast. But I always liked the 35 L better for AF and focal length. If I had one with the AF as good as the 35 and sharpness to match I might like better.
OK, thank you. I also own a 24 L II and I find the image quality amazing. Admittedly, the AF could be a bit faster, but it focuses very reliably on my 5d, even at f/1.4 without AFMA (which the 5d does not have). I guess I had luck with my copy.