The best way to choose a format to edit texts is to ask these simple questions :
Exit. Is it possible to escape from it? No need to form a maze of new habits without knowing one's way out of a format. No graceful exit, high risk of imprisonment. Think of the many slaves of the DOC proprietary format.
Export. Can I transform my source text into multiple formats? No need to learn a new formatting tool if one can't create multiple outputs. Markdown is a good example : it helps create HTML, LaTeX and even looks neat in plain text.
Enpower. Does the format speed my work? A format is not an ideal: it's a way to work. The end result should be increased productivity. If one does better at writing in RTF, then so be it.