The only annoying thing with tmux are recursive sessions. By that I mean when you run tmux on your laptop, then ssh to your server and start another tmux session there. It is suddenly confusing and you then have to escape commands depending on which session you want to interact with.
I’ve been using screen at first remotely for those cases, but eventually bailed out and used my graphical multiplexer locally instead of tmux, or not using tmux remotely when already using it locally.