I went through a similar experience with our code base and saw similar results. Our project is quite a bit larger (some 20k loc) but converting it to React has been a huge win. Performance has improved without all the custom code needed in Angular, bugs are easier to find and fix, and reasoning about the code is a ton simpler. I hate to think about all the time we spent trying to optimize the Angular digest cycle... .

We also discovered that since writing components is so much easier in React than with Angular 1.5 we tend to write a lot more of them. This makes the components easier to test and has greatly improved reuse across the code base. Which in turn makes adding features possible that would have destabilized the old code base.

I did look at Angular 2 and just saw more of the same and didn't want to deal with it anymore. I found that I personally aligned well with the React ecosystem (Redux, JSX, CSS in Javascript) which probably colored some of my decision.