As you have probably noticed Sony launched the new G-Master series lenses some weeks ago. I've been following the discussion about them with great interest and especially the G-master 85/1.4. Now before I continue, I want to emphasize that I'm not interested in putting the G-master 85/1.4 and the Zeiss Batis 1.8/85 to competition since both of them are valid high quality choices, though I understand the ongoing discussion and comparison between them. But since I have already followed this discussion I thought I could add some remarks of my own which some of you might find useful.
Some years ago when I got my first prime lens (the SEL 50F18) for the Sony Nex-5N I was, like any other newbie, amazed about the bokeh I could introduce into my pictures. Having the gradually blurred background gave my pictures a totally new look which I had been craving as soon as I learned about it. Going few years with the crop sensor Sony Nex-5N and the SEL50F18 was great, but during this time I developed a desire for that 'full frame look' and more bokeh. Especially with the 'full body portraits' (does these even exists in grammar?) I noticed that the APS-C crop sensor and the fast f/1.8 glass just isn't often enough for a nice background blur. So I craved for that 'full frame look' and a fast 85 lens but economically they were out of my reach.
So it's only natural that when I was lucky and finally got the Sony A7 and the Zeiss Batis 1.8/85 I was very happy since it promised to cure this need for the bokeh – and it did. But what I never realize at that in my time with the crop sensor Nex-5N I had developed an obsession with the bokeh where I subconsciously thought that 'more bokeh the better the picture'. The problem with this kind of thinking is that focusing on a bokeh isn't the most productive approach to photography. When obsessing about the bokeh one stops looking at the subjects and concentrates too much on the out-of-focus areas which is kind of paradoxical since the bokeh and out-of-focus areas should emphasize the subject and narrative of the pictures, and not the other way around. The quality of bokeh is an interesting photography discussion and will always be, but in real life the background you choose for your pictures often matters more than the lens and besides that the viewer very rarely even notices the bokeh at all since he is concentrating on content, narrative and subject of the picture. In short, the subject of bokeh often receives a lot of attention in photography circles, but it is not so legitimized in real life photography. I think this also shows in the current G-Master discussion as well and for example, I've found the argument regarding the shape of bokeh balls artificial at best – though I really like how the G-Master 85/1.4 renders (see, in my opinion, best examples here by Mark Galer).
It's kind of ironic that once I got the Sony A7 and the Zeiss Batis 1.8/85 I stopped obsessing about the bokeh. I've found that most of the times I don't actually prefer totally melted background as they often wipe out too much context out of the picture. Instead of 'total bokeh' I prefer gradually blurred out-of-focus areas as they are often enough to draw attention to subject but still provide useful information about the context. I can't speak of G-Master 85/1.4 as I haven't tested it enough to provide any useful information, but regarding the Batis 1.8/85 I can say that the sweet stuff happens in transitions between focused and out-of-focus areas – just like the picture here where Aura's hair has a beautiful transition which I think adds into picture. Batis has this really 'dense' bokeh which reminds me of 'gaussian blur' from Photoshop and is definitely a more modern look than, for example, what you get with the Loxia lenses. I believe this comes from the Sonnar design and it's similar to Zeiss Sonnar 135mm lens as well.
Now that I've stopped obsessing about the bokeh I've found that one thing I really like with the Batis 1.8/85 is great contrast and colors it provides already from wide open. I belief it's safe to say that the G-Master 85/1.4 will deliver similar performance and that's definitely one thing that puts both of these lenses above the usual DSLR-lenses which have often had a certain compromised performance at maximum aperture. Choose either one and I'm sure you will definitely be happy about it!