An alternative to Evernote is appealing. To replace EN it would need a web clipper and tags/folders (so far so good, with promised hashtags). It would need great search and navigation (more intelligent search than EN). To improve on EN it would respond instantly to what I’m doing on my device, and not fart around talking to some remote server. It would have a backup function that I could direct to my chosen server. It would of course be private, with no analytics applied that were not also fully available and transparent to me as user/writer. it would have some basic paragraph styles, accept Markdown, and display Markdown text in something like the way that Ulysses does. If it would talk to Ulysses, importing/exporting Markdown files, that would be wonderful - I could use it as the overflow memory-space for all the odds and sods I don’t want clogging up my main workspace/file-system.
Not sure how interested you are in layout styles (minimalism and all that) since Write.as has no bold, italic, indented text or headings (ie no Markdown). For me, a writing environment without formatting isn’t a tool at all. I don’t believe in ‘pure content’ - every text is a document? Others will differ.
I guess I’m more interested in Jot.as than Write.as. Although I favour open source apps, Ulysses is so unbelievably useful that I don’t mind it being proprietary. And I have a sense that you mean to be much more minimal than Ulysses is. Fair enough. Evernote is a pain in the bum, and I would be very pleased to see it displaced.