Okay, here're a few examples. There are probably more:
I've used $.bbq plugin for 'basic' routing (similar API to riot).
It wasn't enough. I was writing tons of boilerplate and my routing logic was fragmented and hard to follow. Sure, this comes down to lack of convention, but that's as I said, a benefit of frameworks that establish said conventions. I'm also not much of a fan of Backbone's router by the way. Ember's on the other hand, looks bloody fantastic.
I've tried every templating language under the sun.
The idea of creating portable/pure HTML/logicless templates (whatever you want to call them) so that your 'HTML developer' can work with them is a fool's gold. If your 'HTML developer' is likely to misunderstand or break your HTML because it contains logic in it, they're just as likely to do the same when there are implicit rules in your templates. If anything, explicit template tags, like say an {{#each}} tag makes them far more likely to tread carefully when dealing with them. But in reality I've found this is all a non-existent scenario. The (JS) developer is going to be the one writing the HTML and translating a designer's vision into the web-app code. That developer is likely to need to refactor templates/partials several times over the lifetime of the app. So whether the designer creates their style-guide as HTML & CSS or not, you don't want them working on the actual app's templates. It seems to make way more sense to have them working on static playground version of the app's markup.
Collections. Boilerplate.
Backbone's Collection and Models are really great and the create/add/save stuff cuts down on a lot of repetitive code. The Underscore functionality you get on Collections are fantastic for opening up your console and exploring your app with powerful things like:
App.Models.people.pluck('age'); // spit out ages in array
App.Models.people.where({ age: 18 })[0].set('age', 19); // see what happens in your view as a result
App.Views.funkyInspector.model.set('active', true).save(); // see what happens in view/xhr as a result...
Riot doesn't give me this. Basically you're not doing enough for me!
