Dutzie, Funny, but Zeiss would probably never get a penny from me!
It's all about shooting styles. Most have a Zeiss super sharp lens and probably don't take very sharp pics with it other than sample shots.
Remember that with a very fast lens wide open, we use them to create art and produce effect. The subject is usually in sharp focus in the center of the lens and everything else is blown out of focus by the DOF at any edge, thus how poorly the edges perform are of no value at all. We all own sharp lenses that are slower and can use them when we need sharp!!
Also at f1.2, on say a sunny 16 day the lens can't even be used, on any camera at 1.2 unless you add ND filters to slow it down!!!
Personally I think most get something like an ubber expensive lens for all the wrong reasons, of which one reason is to just say you have it or be seen with it!
If you have the bucks, go ahead and get one, but be sure you are doing a lot more with it than you would do with a very sharp and inexpensive nifty fifty!
There is a time and place for any lens, and maybe this is your time and place!
Before you drop your bucks, you would get way more resolving power by getting a new 50mp camera at probably a lot less money!! Just saying!! ;-)
SS

PS, I don't think I would put a Zeiss lens on my camera and magic would start to happen over the lens I already shoot. But put a f1.2 lens on my camera and magic DOES start to happen immediately. I can REALLY see the difference between 1.2 and 2.0! good luck!