Yes . I think it's worth upgrading to v0.14 .

Most of the components in our apps are stateless which does nothing instead of composing other components . In v0.14 Facebook has introduced Stateless Functional Components which takes props and returns the element you want to render .

var Container = (props) => {
  	return <Chlid>props.text</Child>;
}

They have better performance as they don't have unnecessary component code . There are a lot of breaking changes which you can see in their upgrade guide.

Also in v0.15 will be no more data-reactid attributes and it's a bit faster .

React core contributor Ben Alpert said "We know changes can be painful (the Facebook codebase has over 15,000 React components), so we always try to make changes gradually in order to minimize the pain."

it's worth to upgrade despite the fact rewriting all import statements. but when using es6 already you'll gain a little cleaner code and help to kill mixins :D