Like so many others I was thrilled when I saw John O'Nolan's inspiring Kickstarter pitch video. (sadly Ghost is still quite user unfriendly) What I've realized since then is that the dual-view editor isn't, for me anyway, that helpful. What mostly excited me was just the ability to use Markdown. I've had bad luck with many WP Markdown plugins, but the Jetpack Markdown works pretty well for me so that's what I'm using everywhere now.

As an aside it's remarkable to realize that every single day I use Markdown, Creative Commons Licenses, and RSS Syndication for every post I work on. Aaron Swartz is gone, and yet he's everywhere.

I installed MarkPress and as you warned, it's a bit hard to get back to the backend. I don't mean to be cheeky, but I don't really get it? It's a WP site that no one who isn't logged in can see at all, not even the "published" work. And it is, what? A notepad? It was a place to type, but I couldn't find a way to index them, give them titles, or do anything with the tags it let me use.

I've been using the P2 child theme Houston from WooThemes (with Markdown) and I really love it. I don't actually see the use case for MarkPress. Whatever it is, it seems like, for me, Houston is a much stronger platform. So far O2 is pretty much long-promised vaporware, but if it ever materializes (around the time of WCSF'14 perhaps?) it also looks to be very useful.