Not sure about the thing about stopping the fans when the CPU is under a certain temp - might work fine for an air cooler but for water, the coolant is going to be at quite a high temp level before the fans kick in if you're only doing light work and then if it's put under heavy load again temps are going to go through the roof, and stopping the pump is not going to work out well at all
I'll do some testing on mine including water temps, I'd love to know how long the test above was run for, and noise levels, wouldn't matter if there was 1 fan or 12 if the tests were only running a couple of minutes
Of course that's not going to take into account better fans, just the Corsair SP120s that come with it, they aren't the quietest but the specs on them are quite beefy to be fair