My guess is the performance benchmarks would be much different if you are dealing with an app with a high number of nodes where the diff/repainting benefits of React really kick in.

Espresso.js diffs as well, except it doesn't have to diff the entire DOM but only the attributes that you'll actually be changing in effect.

Moreover it gives you the option between declaratively specifying the DOM to imperatively manipulating it when you need to for performance reasons.

It's a tiny library and the approach is much more efficient than diffing the virtual DOM for the entire page, so I'm pretty confident that results would actually be even better in larger apps.

React works fine without JSX. var DOM = React.DOM; DOM.div() etc.

Sure - but that's quite horrible to write. And moreover it requires a sophisticated virtual DOM diffing algo, hence the size of React's library.

I prefer to do this:

render: function() { return { view: { classList: { editing: this.model.editing, completed: this.model.done } } } }

Compared to outputting the entire HTML for the component in render().