I guess to a certain extent, less fans would be a consideration. But the main point of water cooling (to a serious overclocker) is lower core temps vs. air cooling, which would provide more room for overclocking. Unfortunately, water cooling solutions are still sort of in their infancy. They aren't that efficient yet, unless you look to the more expensive offerings. So, they require the assistance of air cooling too. I'm more interested in the phase change solutions, which would be similar to putting your cpu and motherboard in the freezer. Which, by the way, you shouldn't try because of the condensation for obvious reasons.