The biggest reason we adopted Immutable.js is that it allows us to use PureRenderMixin (or, to make some situations even simpler, https://github.com/jurassix/react-immutable-render-mixin ) for all our components. This gives a great performance boost, without having to think how to design a specific shouldComponentUpdate for each expensive component.

This is especially important with Redux if you connect your store to one controller-view which then passes the props down to a big tree of components (which should be the standard way to do things with both Flux and Redux).