ember-cli-bootstrap-sassy | a fork of ember-cli-bootstrap-sass | Style Language library

So first of all a disclaimer: as the author of ember-bootstrap, I am certainly a bit biased here! ;)

But I think I have strong arguments in favor of ember-bootstrap, otherwise I wouldn't have invested that ton of work. So the main one is that it follows the programming model of Ember, while using bootstrap.js directly doesn't and would often feel awkward in an Ember app:

• You use components to render things, which in turn render the trivial markup that Bootstrap expects, rather than spreading Bootstrap flavored static markup all over the app
• Components in ember-bootstrap strictly follow the so called "Data down Actions up" (DDAU) programming model in Ember
• that means through declaratively assigning properties which create data bindings, the state of your app "flows" through your UI, so the rendered DOM is a direct function of your state. This is the "Data down" part, which is different than having to imperatively "call" things to achieve the same effect (like $('#myModal').modal('show'))
• When the user interacts with your UI, actions are called, which are handled somewhere up the component tree (e.g. in a controller). These transform your state, which is used to update the UI again (unidirectional data flow)

If that sound too abstract, take this simple example of a modal component. In ember-bootstrap you would do something like this: