TidusJames
Please disregard what that guy says about the H series, he greatly exaggerates the noise, I have very good hearing and it does not bother me if it's on maximum. While on maximum it can be somewhat loud, you can set it to quiet making it only 1c-3c less effective. (I own one)
I would say replace the stock paste too. If you get different fans for the H100i, make sure they have a higher static pressure than the stock fans as they are already good with 4mm/H20.
Liquid all in ones may not be much more effective than a high end air heat-sink too, but you're paying for the cleaner look, and not having a heavy heat sink hang off socket.
Like I said, there will no noticeable difference between the cases in real world usages...