STAY AWAY FROM THE H100i, I am in the process of moving from my h100i to an nh-d15 in the mail on its way.
It buzzes, the pump is loud and the fans are insanely loud. Clcs are inefficient, to try get the same temps as big air coolers they need to have fans that are much louder and usualy much higher rpms. You will eventualy want to swap the fans out from the h100i, but then you will sacrafice temps because the inefficient h100i needs those loud fast fans.
The only decent clc with noise to cooling ratio is the recent coolermaster 240, but still get's beaten by the nh-d15 on temps and noise. Unless you can find a swiftech h220x/240x(very hard to find in stock) always go with a big air cooler.