Comparing
sysutils/tmux and
x11/terminator is like comparing frogs and grandmothers.
sysutils/tmux is virtual console multiplexer which was develop by an OpenBSD guy (he became OpenBSD developer after starting tmux) out of frustration with code quality and bugs of infamous
sysutils/screen. One typically uses
sysutils/tmux inside an ssh session to lunch multiple consoles on the remote server without need for multiple ssh connection. It allows you to detach session and reattach it later. Managing console via panes tiling window management style is just an integral feature.
sysutils/dvtm is just a tiling window manager for console. Nothing more nothing else. It would allow you to have multiple consoles on the remote machine but can't do any other useful stuff like detaching.
x11/terminator Python is just terminal program like a Gnome shell for example. It uses actually the same bloat-ware like Gnome shell.
x11/terminator might be an eye candy but it has no practical use. There were many discussion of alternative shells (to standard xterm) on this forum. While I myself don't use anything else but xterm there are definitely some interesting alternatives in particularly for people needing non ASCII characters.