The most ECMAScript 6 compatible browser? Not the one you’d expect
twitter.comActually, exactly what I expected from the headline alone: an IE Tech Preview does -- when the others compared are the stable releases of other browsers.
Of course, given the relative release cycles, that's like comparing a Chrome version 3 or 4 version numbers ahead of the current Dev channel release against current IE.
The result is the same when comparing nightly builds. Actually IE updates each month now. Previously only critical updates were included on “patch Tuesdays”, but now features are added too. That is not to say that these particular features will be included in monthly updates to the stable version of IE11.