It's not bad... it's just much more light-weight (essentially). So, the bigger the project, the more you're going to feel Backbone strain relative to AngularJS. However, for small projects, you probably don't need such big guns... but if you can afford shipping AngularJS to the clients anyway, why not?

You can see the different styles for yourself for a very basic web application (and try to extrapolate what it would look like for large ones): http://addyosmani.github.com/todomvc/