Oh well, at this point we're moving into subjective opinion. But you need to write your frontend SPA with JS. And the isomorphic part, if designed from the gro

Oh well, at this point we're moving into subjective opinion. But you need to write your frontend SPA with JS. And the isomorphic part, if designed from the ground up adds almost no extra code. So, really it's almost free to render first with Node, if you're starting a fresh SPA. I don't see why you wouldn't want to do it. And we can all agree the ES5 has some warts, so you may as well transpile. Whether it's ClojureScript, Coffee, Type, or anything else doesn't matter, I just think it's a problem solved. Webpack makes debugging them easy with sourcemaps and live-compilation. In fact you can get hot-reloading[1] in React. So your app re-compiles without reloading. I'm happy with ES6 + Flow. It's all ES6 syntax anyway, works with all libraries, and is fast to write, good looking, and functional. [1] https://github.com/gaearon/react-hot-loader https://github.com/gaearon/react-hot-loader