I have the 670 FTW, and when I'm playing games, I never ever hear the fan spin up, even when its on full tilt. This is due to the sound of the games themselves. I will hear it for about twenty seconds after I shut an intensive game down, as the gpu cools, which it does, and very quickly. That being said, I have never seen the card exceed 67 C, and it idles around 27 C. The 680 reference cooler does a spectacular job.
Honestly, I never figured out the problem people have with fan noise. Unless you play games completely on mute, you aren't ever going to hear it. If you aren't playing games, and working on photoshop so much that the gpu is spinning up, and it bothers you, just put music on.