I'll throw my $.02 in here. I just installed 2 MSI GTX970 Gaming 4G cards. From what I've read the MSI Gaming and Gigabyte G1 are the best cards out now. ASUS put an 8 pin power connector only and it limits boost. EVGA cheaped out and didn't do much over stock for their cards and if you OC they aren't anything special. MSI uses Mil Spec parts and bumped up their power on both the GPU and memory. Stock is 4 phase to the GPU, they did 6, which is what ASUS and GIGABYTE did. However, they did 2 phase on the memory, which stock is one. ASUS kept stock and I can't find what Gigabyte did. It looks kinda stock though from pics. Either way, I am MORE than happy with my MSI cards. I have them in a mid tower with decent, but not crazy air flow. The stock fan profile is really good even for most overclocking. The Fan does not even turn on until you hit 60C and some games, that doesn't even happen. I was monkeying around today and got my base GPU clock to 1300MHz and Memory to 8GHz with no effort at all. Though, I run the stock clocks right now because nothing I throw at it tanks the cards. They are extremely quiet too. My case fans are louder... and they are quiet.
However, I have noticed that some games do experience some "funkiness". So far that is Titanfall and PlanetSide 2. My buddy just bought an MSI GTX 980 Gaming and he has the same issues with PlanetSide 2 so I suspect its a 900 series card driver issue. Titanfall doesn't run anything over 60FPS and gets some artifacts, similar to PS2. I suspect there will be driver updates to correct some of these issues, as any new GPU of a new architecture can exhibit.