OP, I was struck by your 'not sharp enough' comments about the 85 1.8. I've had two copies of this lens. The first was not real good at f/1.8. I just looked through my catalog at shots taken with the second copy, which I really like. I have no complaint about the lens' sharpness, though when it matters, DOF is too thin at f/1.8 for me.
I can't see paying the going rate to upgrade my 1.8 to a 1.2L, 1.4L IS, or the Sigma options. I really like my 85 1.8 on 6D. To those of you who've used the better glass, is there that much of a difference in IQ wide open, or up to f/1.8 anyway? Not talking bokeh, but subject matter IQ.
I think part of my problem is that I'm comparing it to two of my other lenses (Sigma 35 Art and Tamron 70-200 [1st gen]) and it seems to fall short of them.