If you're on a mac and use iTerm2, using tmux is somewhat of a no-brainer, thanks to the integration between tmux and iTerm2.
Definitely recommend the switch. You might be dreading it, but two days into tmux you won't regret it. It took many weeks trying to convince myself screen is better until I actually tried tmux out.
tmux seemed slower while switching windows, plus I like the simplicity of screen.
set -g prefix C-a
The only two pains that come with it are a) having to type `` to get a single `, and b) pasting anything containing a backtick behaves as if you'd typed it out.