The one thing Coda or any other GUI based editor is really nice for is CSS. While it's rare at I have to delve into that stuff, it is really nice to have amenities like a color picker and a visual representation of the colors instead of just a hex code. So while I use emacs for my source as well, I jump into Coda for the rare cases where I am making style changes.
I'd love if there was some emacs-y way of doing this, but it's just not good at gui tasks.
I like Coda's CSS Editor, but for CSS Editing alone, you'd be much better served by a unitasker app like CSSEdit.
Sorry for the downvote from whoever… I upvoted you. I think you've got a point.
CSSEdit is a great way to edit CSS. More more intuitive and relaxed, not necessarily better, but neither is emacs necessarily better.
What a program.