I have owned three copies, because I couldn't decide between the 85 L and the 70-200.
I have had one copy that was completely useless, I had it in for repair, they changed TWO AF-moduls and TWO IS-units, they took out the front end, and three glass-elements and re-aligned the glass and when it came back the AF worked perfectly, but the IS was still not starting as quick as the previous copy, and it jumped, and often worked only one direction, and made a very weird, loud noise. It was VERY soft at 200 when I sent it in, and after all the re-alignment of the glass and front end it came back exactly the same. I sold it for cheap and had the buyer try it to see if if he liked it, and he bought, so I got a third copy, which like the two others had the issue of IS not being perfect, sometimes too slow to start, sometimes only one direction stabilized. But the AF and sharpness and overall image quality and build is as good as it gets. Wonderful lens. Just not as good as the 200 L, which is the reason I no longer have it
I had a ef 200mm f2.8 II L and it was a stunning optic, slightly sharper than my 135L. When I got my 70-200 f2.8 L IS II, I compared it to my 200L and found that the zoom had better contrast and colours. Sharpness tthere was littel between them, manybe a slight nod to the prime wide open. But with teleconverters, the zoom was a lot better. The Zoom has the latest IS unit, faster and quieter AF and it focusses closer too. The bokeh of the prime and general flare control was better than the zoom. The prime is a lot lighter and less obtrusive.
I felt that for my needs, the zoom was a better optic.
I think he means the 200mm f/2.0L IS, not the 200 f/2.8L....