Using Razor and Angular.js in an MVC4 environment

In a project I'm working on, our MVC4 website is using a combination of Razor and Angular.js. I'm pretty new to front-end web development, so I'm confused as to if this is a good idea or not. What are the advantages and disadvantages of mixing these, and what are some scenarios that using both of these together would make sense?

I can share our expirience with AngularJS + MVC4/Razor: We're using Razor only for localization - so only allowed Razor feature is "@somekeyword". As result on client side we got localized AngularJS templates. This allows to do maximum caching (even using CDN).

As for MVC4 we're using ASP.NET Web API for sending JSON data. We'd developer extension for sending HAL (Hypermedia) responses.

This gives maximum decoupling and possibility to change to another backend if needed.