You can go for performance and silence on both air cooled and water cooled. The difference being when you go silent on one of these you don't lose that much more performance.
An air cooler when you lower the fan speed you lose static pressure pretty much doubling up on your loss. With the right fans, you can have silence AND good static pressure on a rad that's built for silence. Can't forget either, that heat is released from the block, pump, and hoses in a water system.
I run a 4.2ghz 24/7 folding 3960x with HT enabled on my H50 with a low RPM push/pull setup. You'll probably easily get 4.6GHz with it.