We have skit sitting on launchkit.io, with a REST API in Django sitting behind it (serving prelaunch native mobile clients from api.launchkit.io).
Logged-in requests that load data hit the API first from node, using the same JS API client that runs in the browser. The logged-in user cookie is actually an encrypted OAuth token from the backend API, so our website is actually a first-class API client just like our mobile apps. No separate session logic, etc.
I prerender the first results in the "reviews" list using a template on the server, then when you scroll down the list the additional items are loaded and rendered with the same template in the browser. It seems weird/foreign but in practice it's not that weird.
So far it's been fun, and honestly it's worked far better than I expected it to when I started tinkering.
Would love any feedback / etc., here or on twitter @taylorhughes