That said, I would be uncomfortable mixing something as opinionated as Angular with another framework that expects to "own" the DOM/rendering. My guess is that Angular will implement their own version of VDOM in the next few months since it shows demonstrably better performance.
Pretty much this. AngularJS abstracts DOM manipulation away from the user; by adding React to an AngularJS project, you're giving up on that abstraction. I consider React a sacrifice of abstraction / ease of development in favor of performance.
I think AngularJS will adopt a similar strategy for their 2.0 development effort, maybe even a 1.x point release. But I haven't looked at the angular development process for a while now.
I disagree with this. React abstracts away DOM manipulation just as well as Angular does at a high level. When you dive deeper (i.e. building components/directives) React continues to abstract it away, whereas Angular reveals it.
In fact, React is able to get superior performance because the DOM is abstracted so far away.
That said, I would be uncomfortable mixing something as opinionated as Angular with another framework that expects to "own" the DOM/rendering. My guess is that Angular will implement their own version of VDOM in the next few months since it shows demonstrably better performance.