Apfelbeisser wrote in post #16883271
And I'm lovely landscape photograph and I think, I'll get huge improvement with the Zeiss.
The zeiss will not be what will make your images "magical". The improvement will not be as huge as you make it sound.
Both 85 and 100 can make amazing images. Both are top of the line.
The 85 has the magical 1.2 and when handled correctly, can give stellar images even wide open. And the 100L's IS is amazing for shooting macro even hand held sometimes.
You want to trade two good tools for another which not necessarily make your images several steps better. And it does fall somewhat into user ability to bring the most out of his gear.
The zeiss is sharper, and it renders images a bit different (which is very subjective). For pure macro with MF, it will be superior to the 100L. I don't know if twice the price, but it will be. For portrait, I think its much more subjective. Personally, I have yet to see a lens produce as good out of focus as the 85L (But this is also somewhat subjective).
If you aren't using the 85 to its fullest, and you want the zeiss image rendering, than go for it if its the better tool for you. But don't expect your images to be twice or more better. This I think a more wishful thinking, and even if you do replace both for the zeiss, you will feel obliged to tell yourself its vastly better for the sake of thinking you did the right choice. But overall, I don't think its worth both the 85L and 100L. I would more consider replacing the 100L with the zeiss and than see if its a better tool than the 85 for portrait.
Personally, I would not want to lose the IS of the 100L for walk around. And I will not want to lose the quality of the 85 in terms of out of focus quality.