Honestly benchmarks are useless. I'm sure Elm is "faster" and what not... but does it really matter? React is fast enough for a ton of businesses and people. So is Ember.

Sure, performance is good, but I think mostly bottlenecks are user code and the way the JS/CSS bundle is loaded and delivered. If there's a major performance issue in the framework, just submit a bug report. It'll be fixed.

I'm more interested in how productive I can be and how much fun I can have coding with said framework or language—something both Elm and React do well.

This post is "benchmarketing". The post says: "Here we add a key to each entry and define shouldComponentUpdate for the Todo component. Essentially the same as what we did in Elm, but we have to write some logic to figure out if a Todo changed. This opens us up to some extremely tricky bugs." The author should instead be using immutable.js, so that checking for changes is object identity checking; it's much faster that way and avoids "extremely tricky bugs".

I am not a big fan of react but making generalisations about performance based on benchmarking todoMVC is well not very convincing.

React has never been about speed (if you look at the official dev posts, speed is never listed as a top priority) but rather about not being slow (sCU check and whatnot). It's the slowest vdom implementation I know of, but it's fast enough and the network effects from being the biggest make it good enough. If you're interested in faster vdoms then check out inferno (fast), snabbdom (simple), mithril (compact), or domvm (flexible).