[trungaczne]

I used to use i3 and tmux for a time.

Advantage (of using tmux on top of i3):

When you spin up a new window with i3, it doesn't retain the previous's current working directory. There are some hacks to make it kind of work, none of which work nicely. With tmux it just works.

tmux has synchronized panes. It allows you to send same keystrokes to multiple terminals at once. This is useful for managing multiple host machines at once, i.e. ssh'ing into different machines at checking certain logs.

Disadvantages:

Double the amount of keybindings you need: one set for i3, one set for tmux. i3 allows you to active a mode where keystrokes are 'forwarded', so theoretically you can use the same keybindings for both, although it is very annoying if you forget to active this mode since you're now creating i3 windows instead of tmux panes and have to clean them up.