I too tried out @stephank’s docker-for-mac-nfs yesterday and ran into some initial problems (because I think I did something wrong at first, not because there was a problem with his instructions), but I was able to debug and solve my problems by logging in directly to the docker host VM and poking around there. @stephank’s blog post (https://stephank.nl/p/2017-01-01-inside-dockers-moby.html) and the other blog post he linked from there (http://lucjuggery.com/blog/?p=753) were very helpful for me.
I haven’t done extensive testing yet, but I can verify that docker-for-mac-nfs is working well for me in that it was pretty easy to set up, it is in fact working (I can view and modify shared files), and the performance is not as abysmal as it is with osxfs. I’m not sure how close the performance is to native, but for my purposes it doesn’t matter all that much.
Thank you very much, @stephank for this great, well documented solution! (Though hopefully it is only temporary until Docker for Mac is finally fixed for real. =P)