On a recent Holiday with my Family (current, still travelling), I decided for the first time, I think ever, to take just Manual Focus Lenses, I ended up with the Zeiss 21f/2.8, Zeiss Otus 55f/1.4 & the Zeiss 135f/2, all being used on the 1Dx with the Ec-s screen fitted.
In good light all of these lenses are relatively easy to find focus, once found, all produce amazingly sharp Images with wonderful Contrast.
In poor light it's a different matter, I found Tripod & Focussing via the LCD screen was , at least in my case, a must, again, once focus is found, the lenses all perform better than anything I own from Canon, and I seem to have a reasonable amount of Canon L Glass.
But for several weeks now I've begun to feel more and more attuned to these Manual Focus Lenses, to the point where in my own Imaging I feel with the exception of Wildlife, the Zeiss Lenses will become more and more my go to Lenses for Landscape, Portrait & anything that moves........ sloooowly.