Thanks, although I wouldn't claim it to be "proof" :) and yeah, the choice of ES5 vs. ES6 seems to be a major weakness of the study as others here have said as

Thanks, although I wouldn't claim it to be "proof" :) and yeah, the choice of ES5 vs. ES6 seems to be a major weakness of the study as others here have said as well. In any case I believe switching the current product to ES6 would make the results even more convincing.