Huh, all those are features of tmux itself. I can copy/paste to/from system clipboard, I can easily movie between windows (and could set in my tmux.conf to use

Huh, all those are features of tmux itself. I can copy/paste to/from system clipboard, I can easily movie between windows (and could set in my tmux.conf to use Command-` if I wanted), I can focus panes with the mouse, etc.