Interesting. Just yesterday I decided to start blogging again with Octopress, and conducted a fairly extensive search for a good Markdown editor for OSX, and found nothing impressive. Mau gets tons of attention, as does Marked, but neither does a good job of handling an octopress post with code blocks.
I'd ended up giving up and just going back to Sublime, but LightPaper handles my use case perfectly, so...nice. I think I'll be using this.
Mou is really annoying in the way it handles history. I guess it's author never heard of the command pattern, because Undo-ing the history doesn't consider the autocompletions Mou did and just generally doesn't work and mess up your document. Then Redo-ing helps cementing the mess.
Also the editor is very lacking in functionality, in term of text manipulation.
I started by liking Mou, then working around the issues, then getting pretty angry at it from all the time I wasted trying to make it work - all that just to get a live editor. Ended up setting a Grunt task.
I've reported those problems to the author who didn't seem to give a damn.
After reading your comment I made the switch as well.
For others reference, you can use Jekyll with LightPaper if you switch your highlighter from pygments to redcarpet which supports triple-back ticks (variable 'markdown' should be 'redcarpet' in _config.yml file).
Spent an hour at least changing all my blog posts just so that I can now use this editor without ANY issues at all.
I'd ended up giving up and just going back to Sublime, but LightPaper handles my use case perfectly, so...nice. I think I'll be using this.