I've written X configs by hand, but only to get a few extra pixels of overscan. I've never needed to do this. My experience has always been that things just work. The UI has never been great, in that I need more explanation than the built-in manuals provide – unlike, say, Windows 95, where you can learn everything you need to know by clicking around – but it's not hard to avoid breaking things, and it's not that hard to learn to do new stuff if you have a good book (or, lately, blog post) to consult.