We evaluate coil whine on a case basis, you return to ourselves, we test the card on a quality PSU and if it is audible within a typical case enclosure to a high level, we replace it.
What we do not accept is people returning cards for whine that is only audible with your head in the case next to the card or when running benchmarks with very high FPS (300+) as this is not how hardware is used or because a poor quality PSU is in usage.
Of course if when we power it up and its screaming, it gets replaced, we are very fair on it and on the basis it is a rare problem we see with graphics cards. Millions of people buy VGA cards, people never post on a forum or very rarely post when they get their card and say hey my card has no coil whine, but people do post when they have an issue, because forums are typically used for trouble shooting.