Tmux is another one of those tools whose siren call I'd avoided for a good decade, continuing to rely on GNU Screen. Then, for the last time I reconnected to a split screen and screen lost my splits and tabs - it was enough for me.

Two years ago I finally changed over and I haven't looked back. At this point, when I encounter something where I only have screen I'm rather annoyed by it - and I've set my tmux key mapping to basically mimic what I've been using screen for the last 20 years.

For me, tmux replaced every single feature that I used in screen. On the other hand, I'd be genuinely happy if it existed on the older OSes I randomly have to frequent, even if it's understandably impossible.