There&#x27;s definitely a lot of room for improvement. The V8 team has been working on finishing baseline implementations for all of ES6 before spending significant time optimizing particular features. But improvements are coming quickly! In the last few weeks, for example, ES6 rest parameters got 8-10x faster and Object.assign() is now as fast as _.assign() [0].<p>In general, we will focus on improving the performance of the most-used features first. Arrow functions, generators, etc. are high on the list.<p>[0]: <a href="https:&#x2F;&#x2F;twitter.com&#x2F;addyosmani&#x2F;status&#x2F;699976753255751681" rel="nofollow">https:&#x2F;&#x2F;twitter.com&#x2F;addyosmani&#x2F;status&#x2F;699976753255751681</a><p>(Disclaimer: I&#x27;m a PM on the V8 team)