Fair enaugh, if you handle > 2GB of files, unison is slow at the start, thats right.
I fully get the point with zero-dev deps on the OSX host, but be serious, thats not possible right now. Neither docker works well enough under OSX (under linux, docker-sync is useless) but in most cases you end up installing some of the interpreters, be it ruby/php others to have a decent IDE integration, since not anything can be handled using remote-interpreters.
I really like the idea of the "clean OSX host", but for now, there is a lot to happen that this actually works out ( not only a good solution without something like docker-sync ). That said, i at least expected, that a lot of people will still have a proper non EOL ruby installed ( not 1.9, like in OSX ), and thats basically all you need.
Still, running zero deps, NFS most probably is a good tool and also for huge codebases ( we tracked down huge means rather size and amount, not just amount. 40k files are not issue)