This looks really nice! It's not for me, though. Maybe I'm not a very good systems engineer, but I've got a decent .tmux.conf. Between writing automation and trying to make sense of the mess I've inherited, I'm constantly splitting, resizing, and re-adjusting my work space to suit the task at hand.
what are the pros and cons to using tmux as opposed to say multiple instances of a terminal emulator split up using ratpoison?
I happen to be a vim user. tmux, vim, vim-tmux-navigator, and some comfortable configurations in .vimrc and .tmux.conf can be a force multiplier for one's workflow. If you like vim, then it makes a lot of sense. If you don't, there's still probably some merit, but, maybe less of an incentive.
I've never used ratpoison, but just read into it. Sounds pretty great, actually. If the key bindings are simple enough, I suppose it could be pretty similar. But, as a sibling comment pointed out, it works most everywhere. Where I go, my configuration comes with me.