Was your data mutable or immutable? The former requires you to write shouldComponentUpdate logic that isn't just old == new. If you didn't write any of that logic and didn't use immutable data rendering everything again from the top down due to a single change is of course going to be terrible performance.

If you wanted to be more adventurous you should look at alternative virtual dom implementations http://vdom-benchmark.github.io/vdom-benchmark/. What you'll find is that React is actually the slowest one out there based on performance. For instance, on dbmonster InfernoJS sees 50-100% more fps and on my machine ~20x better benchmark performance. If you want the next popular implementations look at virtual-dom, which is leveraged in a variety of frameworks like https://github.com/ashaffer/vdux, or Google's Incremental DOM, https://github.com/google/incremental-dom.