There's the fact that dom changes related to a given set of events can be made as part of the same changes to the DOM as a whole... which can reduce parts of the render time overall.
However, depending on your needs, a stream of changes may behave differently in different use cases... to me React simply represents in my mind a better way to manage components and rendering logic, combined with something like flux for data and event flows.
That productivity gain is, in my mind, the better reason to use React. Browser performance characteristics change and most of the time you're not pushing the limits but ugly code is forever.
However, depending on your needs, a stream of changes may behave differently in different use cases... to me React simply represents in my mind a better way to manage components and rendering logic, combined with something like flux for data and event flows.