Ember CLI is also awesome, and Ember CLI Deploy is damn cool once you get it: http://ember-cli.com/ember-cli-deploy/docs/v0.4.x/lightning-...
Deployments take tens of seconds. Roll-backs take single-digit seconds. Previewing not-active-but-uploaded versions of the UI is trivial. Everyone does the same exact thing when they deploy (or throw it on Jenkins for even more fun).
Ember is a pretty cozy ecosystem in comparison. You get Babel, JSHint, npm and QUnit - out of the box. Most of which can be swapped out for your preferred libraries.
Ember gives me confidence, that I can keep maintaining the app with very low effort, especially now, that the Ember community is releasing a LTS version.