Not good, but still thousands of times better. And don't forget that you still need to guess where to read from, which better be a very very accurate guess at that rate. Making such an accurate guess is difficult when your runtime is as complex as a browsers, and so even without that extra timing noise no PoC exists (AFAIK?) attacking browsers.

But you know... you're not wrong ;-). I'm just not particularly worried about the likelihood of this attack hitting anything I care about anytime very soon.