I consider the lack of highlighting part of a "calm" interface: the only thing that changes as I type, are the characters that I type. But maybe that's just Stockholm Syndrome after 15 years of Acme! :)

When I need to check nesting levels, I use a little acme-trick: double-click on the closing mark (works for parentheses, curly brackets, quotes, probably more) and it'll highlight everything contained within that level. So if I type (some (big (lisp (expression)))) and want to make sure I got the right number of parentheses at the end, I just double-click on the last one and make sure the whole expression gets highlighted. Here's a screenshot: https://i.imgur.com/Qyvv2K9.png

I don't find I need to do it particularly often when writing Go, though, and if I do... well, I start to think about refactoring to make my function invocation less obtuse, or whatever.