I am running an EVGA GTX 970 plus a GTX 780 and do not have any complaints on the fan noise from the GPU's Now maybe my senior ears are a factor, but even at full load I have not been bothered.
I of course can only hope it stays that way Bill. Mine ran perfect initially and suddenly started giving me the coil whine when I wasn't even doing anything different from the previous days. Frankly I was a bit surprised at how many similar complaints I found after just a brief search. If this were a new Apple phone surely there'd be a whole bunch of sensational articles regarding the matter, alas it is not. Maybe overall it's not so bad but depending on where you live it might be hard getting an RMA based on coil whine. Mind, it's not just a tad of coil noises as one might expect from a cheap psu. This was like scratching on a chalkboard unbearable for me.
Another thing that interests me here is how I've seen videos of people reporting coil whines indiscriminately between vendors. I could consider switching say for an Asus card, but it might just bring another card.
May I ask, do you ever get both cards under full load? I actually haven't even gotten around to setting up my NLE and such, it might well be that during editing it'll just be quiet as a breeze. Probably in most cases games won't even cause issues but something like folding@home or firestrike might be a different matter. Honestly though if you haven't had issues I'd just leave it at that, no reason to start looking for trouble, hehe!
MSI brand seems to have more of an issue with this but so has Asus brand.
Apparently there is a fix of some sort where you go into the Nvidia settings and turn off a setting but I can't remember which one, 3D or Anti-aliasing or something like that. I came across it I think on Tom's Hardware where people were talking about the coil whine and someone was playing around with the settings and the noise just stopped after turning off whatever it was. Not very helpful as I can't remember but maybe something for you to start a google search.