A good article from facebook iteslf: thinking in React
React is good. It follows the UNIX way where each component does a very small piece and tries to do the best. It is very helpful in separating concerns(easier maintenance).
Virtual DOM is also interesting that it runs a diff on the virtual dom to the real dom and only update the necessary part. I am not quit sure about this part. Does React has 3 dom: a real DOM, a virtual DOM mirrors the real DOM and a real-time virtual DOM used to compare with the mirror DOM?
The one direction data flow plus the virtual DOM might really help rendering rich feature widgets with a lot a dom elements like Grid with thousands of rows. I personally have not yet had a chance to test though.
Until now, i am personally not a super big fan of react because all the html is in the js code whereas angularjs really embraces the HTML. Maybe it will change as i have more understanding on React.