It shouldn't come as much of a surprise that the Zeiss Makro-Planar T* F2 100mm ZE lens is a stellar performer. Photo results at its widest f/2 aperture are impressively high in the centre (although not quite as great in the corners) while stopping the lens down towards f/8 improves consistency, with sharpness maintained to an excellent standard. Even at f/22, where other lenses are already compromised too greatly by diffraction, the lens manages to record a superb level of detail.
It's not just in its sharpness that it impresses, though. Next to all the major macro options from the mainstream manufacturers, it records a negligible amount of chromatic aberration, while its control over distortion is almost as good, only marginally bettered by Pentax smc D-FA 100mm f/2.8 macro WR and Sigma's 105mm f/2.8 EX DG OS HSM. As such, it's a great option for architecture or technical work, where such aberrations need to be kept to a minimum.
Overall then, the Zeiss Makro-Planar T* F2 100mm ZE lens is a joy to use, and can deliver the quality results suggested by its asking price. Without the provision of autofocus or a life-size 1:1 reproduction ratio it clearly won't be for everyone, while it's asking price of £1,550 will only further place it out of the reach of many.
Then again, this isn't a lens necessarily aimed at the mass market, but one quite clearly built to a standard rather than a price.