Sure, the issue is that it doesn't gracefully degrade when presented with 24bit color.

Tmux does, though!

I used iTerm2 for a while before realising that tmux automatically maps 24-bit colors to 256color. It works well enough for me that I switched back to Terminal.app.

Well, assuming 24bit—or anything from a terminal emulator, really—is not a very bright strategy.

Depends on your colour palette :-P.