The underlying value proposition by any sort of blogging engine (Posthaven, Medium, Svbtle, et al) is limited to a network, ease of use, and a good design. For most tech people, ease of use is a non-factor (you can extol 'distractions-free design', but you can put vim or Byword in full-screen mode) -- and I think the way people are reading is shifting away from individual sites and towards external services to the extent that design isn't a huge factor (everything looks the same in NewsBlur or Instapaper.)
This leaves the network/audience, which is a much more interesting concept: Svbtle is clearly going for a more curated approach (though the value of that curation is arguable), whereas Medium's trying a bunch of stuff at once (collections, editor's feed, etc.)
I can't help thinking that the winner of this nouveau publishing spectrum isn't going to be a hosting service, but a linking service. You might never get Patrick McKenzie to blog on your platform (because why would he?) but you can always link to his material.