I used Knockout.js on a project before switching over to Backbone.
My experience was that while Knockout is great for simple projects, it becomes a lot more complex than Backbone once things get complicated.
All those data-binds in the HTML get really annoying and the application becomes difficult to maintain. I like my templates clean.
Backbone takes care of syncing your data with the server, provides you with an event system so you can subscribe to changes, gives you a sane convention for how to structure your views and then gets out of your way.
It's also easy to extend, so you could write your own data-binding system if you really need it. A simple 1-way data-bind is quite easy to implement.
If you aren't writing a single page app and only need to make a primarily static page more interactive, Knockout is probably the right choice.
If you are writing a single page app, you often need to sync your models and collections with the server, or if your UI is very complex, Backbone is probably better.
I believe you, but would just say that for me, syncing data between the browser and the server is pretty easy; it's syncing data to the DOM that's challenging. I totally believe Backbone is great that that, but it makes design tradeoffs for syncing to the server too, and I just found no benefit from that.
Anyways, I think we're saying the same thing. The question: how is Backbone better than jQ; many answers; Ko.js as a middle ground.
I want to echo this last remark. We often need to sync with the server and our UI can get to be relatively complex. Backbone is an outstanding tool for us. However, we don't have single page apps (yet) and we've removed any routers from our apps since they were unnecessary.
I believe many of the references on the web regarding Backbone (blogs, tutorials, stackoverflow) actually confuse matters and made my team's learning curve steeper than it needed to be. Also, the Backbone documentation isn't particularly newbie friendly. I strongly advise anyone first looking into Backbone to ignore Routers completely until the relationship between Models and Views is understood, and you've deciphered the patterns that express that relationship.
We also use Coffeescript, which increased the trouble of learning Backbone. But it was well worth the extra head scratching.
Backbone takes care of syncing your data with the server, provides you with an event system so you can subscribe to changes, gives you a sane convention for how to structure your views and then gets out of your way. It's also easy to extend, so you could write your own data-binding system if you really need it. A simple 1-way data-bind is quite easy to implement.
If you aren't writing a single page app and only need to make a primarily static page more interactive, Knockout is probably the right choice. If you are writing a single page app, you often need to sync your models and collections with the server, or if your UI is very complex, Backbone is probably better.