I just tried the 25mm T1,5 cine version, and i was really satisfied with that one. The build the price, the picture it can make.
Yes it has no eletronics in it, and the focus ring is designed for movie-like slow but steady moves, so its a bit harder (but fluent!) to turn, than a regular photo lens.
In a fast/random changing situations i would miss the lack of autofocus, since its hard to keep in focus, especially for someone with no experience, but other cases i wouldnt think its a problem.
One more thing: of course the camerabody (5dmkIII too) couldnt communicate with the non-existing aperture motor, it asked for verifying if there is any lens attached every time i turned it on again. Not a big issue eithet.
Thanks Kankalin. When you change the aperture value on the lens using the aperture ring, does it show the changed value in camera's viewfinder, quick menu? Also did you have to do any AFMA or was I sharp out of the box.