Full screen acme and the rest full-screened in "other window", one cmd-tab away. I try not to IM while working :)

I really wanted to like it, but the lack of syntax highlighting drove me nuts.

I got used to it (at least for go.) I use acme for go and at the same time a full-screened emacs for html/css (and gnus) at the same time. Works far better than expected, speed wise.

Partly matter of taste, partly matter of code formatting style. Used to be big on syntax highlighting for years, but now I prefer mono. When needed, double-click highlights area between matching parens/brackets/braces/tags.