I went back to Rails for my latest project (personal / family photo store) and have been having quite a bit of fun with it.
The project had reached a bit of a crossroads, where the basic proof of concept was in and working, and it was actually functional. I have an idea of what the app should look like, and I've used it enough to know a few things that work well and a few things that won't work the way I had initially thought they would.
Basically, I had a prototype. And we all know the rule for a prototype: throw it away. But that means I need to know what to replace it with.
While my last project with Ember.js was a success, it performed poorly on mobile devices. However this project is not going to be mobile specific, and I can have a basic (js-lite) front end with minimal functionality for mobile. (Basically, I want to be able to upload photos from my phone, but I don't need the photo management tools on the mobile version)
(I hear the word "mobile" in my head with a British accent. It makes me feel proper.)
Another developer I've been working with recently has been advocating vanilla web development with turbolinks for speed. And I think that could work well, for a certain class of application. But that's not the application I build.