If you're developing a desktop-only app (or you're making a native app for the mobile frontend) ES6 works pretty well. At least I haven't received any complain

If you're developing a desktop-only app (or you're making a native app for the mobile frontend) ES6 works pretty well. At least I haven't received any complaint yet, and if you can optimize early on without any short-term cost then it's the best thing you can do. Thank god Chrome and Firefox dominate the market.