The H100i is definitely going to be better for overclocking. Water cooling will almost always beat air cooling, unless you get a Noctua NH-D14. I hate the stock fans that come with the H100i. I picked up a pair of Corsair SP120's for my H100i and they work very well. I have my 8350 at 4.8Ghz 1.52 volts. Your CPU might be a better overclocker, or it might be worse. Just hope that you get a nice binned chip.