Coil whine is a fascinating beast for me as I never ever have had it with any GPU I've bought.
You sure are aware of these discussions going on regarding the FTW and the supposed "design flaw" with missing heat dissipation for the VRMs. As the Hybrid does actively cool these, did you encounter any sorts of weird behaviour, like black screens, artifacts, the card not properly waking up from stand by or whatever?
Regarding the noise I can suggest replacing the stock fan ON THE RADIATOR with some aftermarket fans like Noctua or Corsair SP 120 quiet edition. Those should bring down the noise significantly. Of course, you will still have the fan blowing on the VRM that you cannot easily replace, but that fan shouldn't be that noisy in comparison.