The main problem with client-side rendering is not the parsing time, the problem is the HTTP requests that have to complete before you can start parsing. Whereas parsing on the server side is done in milliseconds by any dynamic document, including this HN page.

While parsing time may not be an issue on client-side, on server-side the situation is a bit different, "server side is done in milliseconds" does not mean it is faster than client side, cf. this presentation [1]. Moreover, I thought that Flux was the solution to the latency introduced by the multiple HTTP requests.

[1] http://www.slideshare.net/nickdreckshage/react-meetup

When this thread started off with the comment saying apps being isomorphic/universal leads to them being "SEO friendly and fast rendering times on first visits" it wasn't about React rendering speed, it was about page load times. First-time visits mean when there the browser hasn't cached various page elements.