One of the things I really wish Ember would focus on is reducing the amount of JavaScript shipped to the browser. I just tried out the included project with ember-cli, and the default JavaScript bundle is 2.7 MB (591 KB gzipped)[1] for an app that doesn't have any functionality. I know that you get a lot with that 591 KB (Ember's router, the Glimmer VM, etc.), but it's still much more than what you can get your React app down too, especially on initial load. For comparison, my _entire_ React application (which includes emotion, react-router, and a full data synchronization library) is only 356 KB (104 KB gzipped). Don't get me wrong: there's certainly applications where the size of the JavaScript doesn't matter, and I think Ember is _great_ for those use-cases. I just wish it could be used for smaller, mobile-focused applications without being several times larger than an equivalent React app.
[1] Apparently this is the development size. The production size is 712.29 KB (180.80 KB gzipped). My point still stands though.
[1] Apparently this is the development size. The production size is 712.29 KB (180.80 KB gzipped). My point still stands though.