If you're happy with your screen setup, there's not that much benefit imo, but I made the switch a while ago and have been happy with tmux. Highlights for me:

If you're happy with your screen setup, there's not that much benefit imo, but I made the switch a while ago and have been happy with tmux. Highlights for me: better support for vertical splits/panes, better mouse support, and more convenient scripting features (for instance, integrating xclip and the tmux copy/paste buffer). It's possible that screen has caught up in the last few years, but I haven't followed its development.