Lenses are one of the most critical choices when you are mounting the Canon 5D Mark II to a lens. Do not treat this camera like it is a film body. Remember to mount the camera to the lens, not the opposite.
Zeiss lenses produce a colder, contrasty feel. They are incredibly sharp which is an important feature in HD capture.
When an image looks a little soft, you loose your depth and snap. A 32 pitch focus gear mounted to the lens makes it easier for your focus puller to deal with the after market focus rings.
Be sure to use more fill light when using these lenses and also control your highlights. Increased contrast means that certain detail is lost such as the subtle features of a set, face or location will be lost in the highlights and the blacks.
What excites you about the Zeiss lenses? I would love to hear your experiences on the set.