I don't have zeiss in ZE mount, but I've got a few in P6-mount, and my Takumar 50/1.4 and FL 55/1.2 are both very nearly zeiss-built, silky smooth focus rings and metal barrels.
I'm perfectly happy using them all on Manual Focus, most of the time I trust my own eyes more than I do AF. I've only got the stock 7D-screen, but the Katz-eye split-prism is on its way. For what I use it for, most static and slow-moving subjects, live-view on 5x is accurate enough, even at 55mm f/1.2.
I've also got the EF 85/1.8 and EF 100/2.0, in low light gigs, shots from across the room, the AF sometimes shuffles back and forth (maybe up to 20cm in real life), wide-open that means the shot is just wasted. So if i'm shooting a performer at a fixed distance, most of the time i stick it to mf anyway.
If the prices were the same, I'd take IQ > AF any day (under 200mm at least).