Unless they improved the fans on the cooler from their 7970, I don't think I could tolerate the fan noise, especially with my case. I use a Corsair 500R, which has a big open side grill. In addition, my PC sits on top of a cabinet next to my desk at about ear level when sitting in my chair. The fans on my Gigabyte card by comparison are inaudible even under full load, as they never exceed 50%. I do know what they sound like full throttle though, as they run at full when in the bios or on system startup (I think all cards do this), and in gaming they never come close to that.
I'd certainly take higher potential overclocks with the possible ability to increase voltage past 1.175 (looking forward to confirmation on this), but for me, it's not worth the additional fan noise.