I just checked Datanyze which crawls the Alexa 1m and more to see which services & libraries websites are using. They've detected 234,003 sites using Angular and 2,069 using React.
I say that as someone who thinks React is the future of JavaScript development and there's no chance I will ever go back to separate templates so Angular of whatever version is just automatically disqualified. It would be like going back in time and I do not want to do this.
It works really well. Including breakpoints in chrome,etc.
I really hope that React makes this more public - it makes it for quick and dirty prototyping. P.S. love ES6. Performance be damned!!
Both are meant for engineers, if by that you mean developers.