Unless their boards are laid out exactly the same (which they aren't if you google image search "gtx 680 pcb" and "gtx 780 pcb" and compare the results), the reference cooler won't fit on the GTX 680. You'll probably be better off with the stock GTX 680 cooler or a good aftermarket cooler like...
I just fixed my PS3 last week by baking its motherboard. 425F for 8 minutes, aluminum foil over the caps and anything else that might not like high heat, let cool for 30 minutes and it works like a charm now. Maybe I can get through The Last of Us before it dies again!
Scythe Slipstreams are excellent fans for intakes/exhaust. They move a ton of air but have poor static pressure, so don't count on them to push air through densely packed fins on a radiator or heatsink, but in open air, they are very good performers.
No, the ones immediately adjacent to the radiators are probably shrouds. They reduce the 'dead spot' that the fan motor creates when mounted directly on the radiator - it can't push air through the area directly in front of its motor.
You'll be happy with it! I have one and it demolishes everything I've thrown at it. It was expensive, but it'll continue to destroy games for quite some time.
I have the EVGA ACX cooler and I'm glad I went with it, it's very quiet and keeps the card quite cool (70C overclocked on multiple Heaven runs), though the Windforce wasn't available when I purchased mine. It's probably a wash as far as performance goes, and I've never had trouble with either...
I just bought this case for about the same price a while back and the build quality is fantastic. It does a great job of sound muffling and had an enormous amount of space. I love it's styling as well. Highly recommended!
I have the ACX cooler on mine, but it (even overclocked) runs around 70C during repeated Heaven runs. That sounds like you have an issue with heatsink contact, too much/little thermal paste, or a fan that isn't working, especially if you can't hear it. Even the quiet ACX cooler starts making...
Distilled water becomes slightly ionized in the loop and the second it leaks on anything in your system, it becomes conductive. There is dust on the components in your system and any number of other contaminants that make the water conductive immediately. In my old loop, I had a small leak on...