Ember.js offers a good framework for JSON and JQuery in a fairly slick MVC with a good VIEWS API binding that will eliminate a lot of the grunt work of building JS applications. There seems to be a strong development team that have
created a good breadcrumb trail of information and tutorials that won't make you feel like you're searching for the holy grail in attempting to learn the core structure so you can start building. As with any framework you are confined in the methods and in the getting and setting of functions but Ember.js uses an object binding method that is quite lucid and adaptable to large scale JS application building.
The learning curve is not a deal breaker if you're looking for a well-structured framework that will prove to be a productive coding platform to launch and maintain any JS based application. The syntax is semantic, allowing you to tie into JSON objects and JQuery calls with little fanfare and the object binding is as you would expect and allows for dynamic changes both in presentation and data manipulation. Code flow is easy to follow and uses a declarative type of hierarchy that not only makes sense it also allows for good troubleshooting when something is not working as expected
One of the most useful methods I found was the string manipulation and dynamic binding which allows variable resets on dynamic data variables. There is a growing number of application templates and wrapper development that will allow incorporating various libraries, plugins, and widgets. The CSS binding methods are strengthened by the core Views API and can be used to streamline the CSS markup.
While Emer.js is flexible and intuitive, one must consider that if your building a JS based application then mapping your code needs is still important so you don't paint yourself into a corner and find yourself with no options on progressing forward.
If you're considering a good framework to build JS applications then I suggest giving Ember.js a strong look for its ease of use and intuitive syntax along with its growing arsenal of tools and wrappers.
by Jim Atkins 'thedosmann'