My bad :x JSFiddle is unusable on mobile and I assumed it was using shouldComponentUpdate. Anyway, the conclusion still holds, you can refactor your code to be

My bad :x JSFiddle is unusable on mobile and I assumed it was using shouldComponentUpdate. Anyway, the conclusion still holds, you can refactor your code to be performant while keeping in the React paradigm. You have a lot less control over the performance of your app with data binding.