(Whoops, my previous comment was confused.) Here in Safari the iterator version is about 25–30% faster, but if I rerun the benchmark cells a few times something goes wrong and both versions slow down significantly.

For me, generators in https://observablehq.com/@domoritz/yield-vs-iterator-vs-callback are faster in safari but this benchmark shows that Arrow 4 is still faster. Maybe because we used to use yield *.