The internet is full of people replacing the fans that come with the H100i and, well all of the Corsair Hydro series water coolers really. So what I'd like to know is how much of a performance drop do you see after doing this, after all the stock fans have an amazing pressure rating of 4mm-H20, none of the quiet fans I've seen have anywhere near that, even the Quiet High pressure fans Corsair sell are only 1.29mm/H20.