As markE said, you have to test performance by yourself. It is really depend on what type of application you have. KineticJS may be slower because it has really high level architecture, and my opinion that event model of KineticJS is the best.
If you need as fast, as possible. Don't use any library. Just "pure" canvas.
You can look at my performace test here: http://slash-system.com/en/comparing-drawning-approaches-for-web/. In this case EaselJS has the best performance results. (I was not doing any hard optimization for each library, just simplest way, also the FastLayer class was introduced in new KineticJS version, I was not using this type of layer.)