The react dev-tools has a profiler which helps get render times and sees what elements are updating when you interact with the app.

However it was missing, seems that it's disabled for production mode, took a while to find that out.

[url gist.github.com/bvaughn/25e6233aeb1b4f0cdb8d8366e54a3977 How to use profiling in production mode for react-dom]

Also I want to be able to access components with $r found some referances to it, but nothing very clear.