Also wanted to ask why do you think that ace is a pain? I agree that it's big, but seems to work ok?
I can't speak for the GP, but my problem with ACE et al. is that they replace the textarea with their own HTML structure (e.g. a div for every line). I understand the reason why, but it means they have to reimplement all the textbox behaviour and they never get it completely right.
For example: when I double-click on a word in the textbox I'm writing this in, and then middle-click somewhere else, the word gets pasted there.
In ACE, it pastes a different text in a different location.
ACE is brilliant if you want to a full-fledged text editor. But it's an overkill if all you need is a normal textarea with some colours.