I used Ember for almost 2 years. My experience was mostly good (see my comment regarding Ember Data--which apparently has no counterpart for React), but it enforces breaking things up into separate files a little too stringently. Routes, Controllers (at least until Components can safely replace them), Components, Templates, and Helpers (even for the most trivial operations which, IMO, are OK to sometimes include in the view).

Not to mention Ember does not use standard ES6 classes yet.

You can scrap most of Ember and just use Glimmer Components, but then all you have is a View layer, so you are not much better off than you are using React. And you __still__ have to use separate template files and helper functions.

This is a side-topic, but I recently attended a Yehuda Katz talk about glimmer. It sounds great. I'm personally really fond of ClojureScript. Glimmer seems to be very much tied to its own tooling and ecosystem. Do you think it would be possible to target glimmer from a functional programming language like ClojureScript or Reason without jumping through a ton of hoops?