The best review of the Zeiss Otus 55mm f1.4! And he really nails what you can do and watch out for when using a 50mm. This guy knows what he's talking about.
I've been drooling over this lens since it's development announcement from Zeiss and have talked about it on my own blog about a year ago. When you watch the Zeiss video of the prototype, it just blows your mind how good this lens is. Sharpness. Color resolution. AMAZING. Little surprised with the amount of vignetting. But nothing even the simplest photo editing software can't fix with ease.
I use my Zeiss 50mm f1.4 for about 95% of my work and have used it for about 2 years. The sharpness, bokeh and contrasty nature of the lens is something I really love about Zeiss lenses. You either love it or hate it. At f4, it's sharpness is fantastic. Construction is second to none.
While I think the Zeiss Otus 55mm lens will improve any image on any modern DSLR, I don't think you'll fully utilize it's potential until you use it with a high MP camera like the D800. I've seen pics with the Otus and D800 and it's getting VERY close to MF quality. I'd like to see a comparison between the D800/Otus and MF camera system. That would be very interesting.
I've said on this forum on multiple occasions that to move up the image quality ladder, MF would be the next step. The DR on such cameras can't be touched by DSLRs. Though a friend tells me that he prefers his Nikon D800 much more than his PhaseOne IQ180. And there is a $30,000 difference between the two. So that's saying lots. I'm hoping that when Canon gets around to releasing a big MP camera and with the Otus lens, it will get me extremely close if not as good as MF quality. And it could do that for significantly less money :-) Even if costs were not an issue, MF cameras have issues. Mostly, they are slow. The D800 looks like a race horse next to them.
I heard that the next Otus lens Zeiss will be releasing will be the 85mm version. And for pro work, this is what I'd probably get if I had a camera that could fully utilize it. It really is the standard in the fashion/portrait biz.
I think we've been living in a golden age of photography for the last two years and this will continue for another 3 or 4 before things settle down again. It's an exciting time to be a photographer!