We have been using [Bublé](https://buble.surge.sh https://buble.surge.sh) as our transpiler, and it's output is extremely readable. Bublé only supports a subset

We have been using [Bublé](https://buble.surge.sh https://buble.surge.sh) as our transpiler, and it's output is extremely readable. Bublé only supports a subset of ES6, but I think that's a worthwhile tradeoff for better debugging. Sourcemaps are nice too, but sometimes you have to go under the covers to find the real problems.