YES, THIS! Setting up directional pane navigation to work with both tmux and vim panes as first-class entities was a huge workflow boon for me as well. It was a significant change that helped kick my setup over into vim+tmux+zsh as IDE vs. merely a collection of separate parts.
It's worth noting that some relevant bits of @mislav's stuff has been packaged up nicely as a Vim plugin:
https://github.com/christoomey/vim-tmux-navigator
I also just noted that @tarruda (of neovim fame) chimed in on @mislav's gist with his own independently created version of the Vim-side of things. It looks worth comparing some of the implementation details from @tarruda's work, he's done some stuff to eliminate redraws in Vim, etc.