Recs.
Updated
SpecsUpdate
Pros
Pro Easy to learn
Learning Aurelia basically means learning EcmaScript and HTML, since Aurelia is designed for standards compliance. Also, Aurelia embraces upcoming ES language features by convention, such as ES class decorators for dependency injection, encouraging clean architecture and future-proof code.
Pro Data binding choices with sane defaults
Aurelia defaults to one-way data binding, alining with conventional wisdom. However, there are times when two-way data binding proves useful, such as binding an input widget with a view-model. Aurelia makes two-way data binding available to developers and uses it by convention when appropriate.
Pro Provides dependency injection
With dependency injection, you can load in extra javascript and new functionality just when you need it.
This is particularly helpful with testing as you can swap out services for test services.
It also means in single page apps you can load dependencies only as you need them instead of loading them up all up at the start.
Pro Variable binding helps with self-documenting the code
The syntax used to bind variables within the application class is very similar to Javascript itself. You can specify the type of the binding you are using explicitly, which practically self-documents your code and makes it easy to understand whether a value is one-way or two-way binded.
Pro Plays well with other frameworks
Aurelia can be used alongside of React and Polymer, since it is designed for interoperability. In practice, this means Aurelia developers can use React components by including an Aurelia custom element.
It also works well with Polymer, since they are both based on the WebComponents standards.
Pro Allows developers to build their application however they want
Aurelia is extremely unopinionated and was designed to be highly modular. This gives the developer the freedom to develop their application however they want, without forcing them in paradigms or rules predefined by the framework. Likewise, any of the individual components can be swapped out if so desired.
Pro Great documentation
One of the most crucial pieces of any new technology or framework is the documentation. At present even though Aurelia is pre-beta, the documentation is pretty complete. There are code examples missing and whatnot, but for the most part it is concise and makes the main parts of the application easy to understand.
Cons
Con Two-way data binding is often considered an anti-pattern
Two-way data-binding means that a HTML element in the view and an Angular model are binded, and when one of them is changed so is the other. One-way data-binding for example does not change the model when the HTML element is changed.
This is a rather controversial subject and many developers consider two-way data binding an anti-pattern and something that is useless in complex applications because it's very easy to create complex situations by using it and being unable to debug them easily or understand what's happening by just looking at the code.