I have briefly tried it. Workflowy doesn't play nice with evernote (or attachments). I think there is some magic in how evernote works, and adding some more robust outlining in notes isn't a bad idea.
Totally agree! It is better to take a step back to get it right than to ship something half-baked. It seems to me that markdown is a decisive feature, and power users don't mind "working for it". Perhaps it is a preference?