I've used both React and ExtJS. Overall React is much easier. ExtJS becomes a mess of event handlers, just take a look at all the possible events when working w

I've used both React and ExtJS. Overall React is much easier. ExtJS becomes a mess of event handlers, just take a look at all the possible events when working with their trees. In theory it looks great, in practice it's hard to follow the code and performance is terrible. The two way binding causes all sorts of headaches including the usual remove listener, update model, add listener type code. It's difficult to follow what code updates what part of the DOM. With React I only need to look at a component's render function. Same with the component's state.