I was a very long time screen user and tried tmux early on in its existence. It was slow and different so I bailed back to screen. Last year I tried tmux again and have switched to it full time.
One of the things I like most about it is how easy it is to extend. In the role I was in last year, I'd have several long-lasting SSH sessions to various hosts. With a very simple bash script I was able to create a prompt in tmux that I could trigger to ask me where I wanted to ssh to. If I already had a connection to that host, it would switch me to that window, if not, it would create a new one and ssh to the host.
I wanted to do that in screen for years, but it just didn't have the features to facilitate it. On top of that I was able to easily re-map all of the keybindings to be just like screen for my muscle memory.
One of the things I like most about it is how easy it is to extend. In the role I was in last year, I'd have several long-lasting SSH sessions to various hosts. With a very simple bash script I was able to create a prompt in tmux that I could trigger to ask me where I wanted to ssh to. If I already had a connection to that host, it would switch me to that window, if not, it would create a new one and ssh to the host.
I wanted to do that in screen for years, but it just didn't have the features to facilitate it. On top of that I was able to easily re-map all of the keybindings to be just like screen for my muscle memory.