Raymond,
I’ve been thinking also about converting my writing from Markdown to ReST and Sphinx, mostly to learn a new tool, but I’ve been forcing myself not to, to keep focused on writing. I’ve also forced myself to write directly in the 750words writing screen, mostly because I enjoy the writing stats, but also to force myself “down to basics” and focus on writing and not on editing, which would be made much easier if I wrote in Emacs, my usual editor of choice. Still, I use Emacs for editing my code snippets and then just paste them into 750words. After finishing each entry, I merge it into my per-chapter text files using Emacs, but I try hard not to make any changes into the actual text.
“Write first, edit later” has taken quite a bit of determination and willpower, as I’m normally a sucker for tinkering, be it with new tools, formats, languages, or whatever. However, it’s been worthwhile, 13 days in and I’m now the proud owner of a 45-page proto-book already, so I’m quite happy.