My current setup consists of an OS X host machine in which I run iTerm. From inside iTerm I ssh into a second machine in which I do all the development. In there I run tmux, and inside tmux I run Spacemacs.
The experience is quite smooth with the only exception of copy-pasting. When I copy/paste from inside emacs, it interacts with the second machine's clipboard. Is there any way make it also use the host's clipboard instead? I would imagine that for copying it could execute a hook after each yank that would send via ssh the copied text to "pbcopy" in the host machine, and for pasting it could have a custom registry that would use the host's "pbpaste", also via ssh.