While testing the Zeiss 85mm two weeks ago, I ran into Katie at the Sarah P. Duke Gardens and made a quick portrait.  While I’d really need to have them side-by-side to do a more thorough comparison, it seems that the Canon 85mm f/1.2L Mk. II has far superior bokeh, but that the Zeiss might actually be a sharper lens from f/2.8 and smaller–but the Canon would definitely win at the largest apertures.  Either way, the Zeiss has fantastic micro-contrast, good bokeh, and clearly has potential for portraits…so long as your subject understands that it will take a second to (manually) focus!