I think we need to see some numbers on ts speed. This benchmark shows ts is faster than babel btw https://github.com/v8/web-tooling-benchmark. Maybe there is a better one somewhere? You can also run compilation and type checking in separate threads as in the examples here: https://github.com/TypeStrong/ts-loader/tree/master/examples. The HMR example rerenders in about as much time as it takes to save and look at the browser.