Two-way data binding really is very convenient, even if it doesn't scale well to large amounts of data. It still saves you a lot of jquery-style boiler-plate code to read values from once place and manually update it in several other places in the DOM.

Also, Angular forces structure on you in ways JQuery doesn't. It makes unit testing viable. I rewrote a javascript slider in Angular, and the code became a lot simpler, shorter and more readable, exactly because of all the stuff Angular abstracts away.

So in comparison with JQuery, the previous best javascript library, Angular has some very clear improvements. How it compares to Ember and Knockout, I have no idea.