Ranked in these QuestionsQuestion Ranking
Pro Easy data binding
Pro Easy to learn
Has a low entry barrier and an easy learning curve. It's especially easy to learn for beginners.
Pro Built in templating
Bindings in Knockout can also be used to control the generated structure of the HTML. There are bindings provided to allow for iteration and conditionals. The structure of the html reflects the structure of the data so iterative elements are bound to arrays in the data model. Having the HTML structure maintained by bindings keeps the templating simple, easy to read, and maintain.
Knockout also allows for string based templating so you can use whatever templating library you prefer.
Pro Legacy browser support
Supports a large number of browsers, including IE6.
Pro Great documentation
The excellent tutorials with built-in exercises are a great learning experience, even for people without prior MVVM and data binding experience.
Pro Lightweight and plays nicely with other libraries
Pro Dynamic models help with keeping the code simple and clean
Models in Knockout can be watched to keep the page data up to date by using observable objects. The observables notify Knockout when data is changed and automatically updates the page when this happens. By having Knockout maintain this relation, it keeps the front end code cleaner and simpler, and by enforcing a consistent pattern with observables the methodology can be more robust.
Pro Very flexible
One can do a lot of things and it keeps self references and other types of loops under control.
Pro It's only a library
Knockout does one thing, and does it well. It doesn't try to take on more than one area. It does MVVM data binding and that is it.
Pro Simple manageable modules
Using components is a great way of breaking up large modules into simpler ones.
Pro Support for a composable component oriented architecture with directives
Angular uses the existing HTML structure and builds on top of it instead of requiring you to learn a new templating language. Because it's just vanilla HTML, it is more familiar, and easier for beginners to learn. Directives let Angular know which HTML elements are under its control, and how to use them.
Being directly on the HTML it's more transparent what's going on, and it's possible to get a good idea of what the page is doing just by looking at the template.
Also, it makes embedding possible, as you could have an angular app within an existing site so you don't have to rewrite everything at once.
Pro Easy and straightforward data-binding
Data bindings are done on the DOM, which allows you to easily sync data between various parts of the DOM in a very succint matter.
<span>Insert your name:</span>
<input type="text" ng-model="user.name" />
This snippet shows how the model attribute "name" is easily bound across different parts of the DOM without having to set up any extra boilerplate.
Pro Provides dependency injection
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 Huge ecosystem of third party components
Pro Huge community that is quickly growing
Pro All best practices
Con Slower than others when amount of objects grows
Knockout has a bad performance when the dealing with large amount of objects. You can see more here.
Con Can become complex once the application grows large
Knockout leaves the application structure to the developer and it can become quite complex and unmanageable in the hands of a beginner once the application grows large and complex.
Con Two way binding requires a little extra work
When allowing users to edit existing data, the two-way binding of observables means you'll need to have to save original values before they're edited, to make comparisons or revert if the user cancels the action.
Con Steep learning curve
Angular isn't a simple framework, and because much of the magic goes on behind the scenes, it isn't easy to go from simply using the framework to being able to actually change how it works and extend it.
Con It is almost mandatory to use Typescript
Although ES standard can be used, most of the documentation and resources are with Typescript.
Con HTML template does not comply to standards
Attributes are case-sensitive, which is against the HTML standards.
Con Difficult to use for isomorphic apps that render the initial template on the server in a performant way. Non issue for enterprise apps.
Con Explicit configuration
Users will usually need to specify stuff that is very obvious (template location, providers etc. ).
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.