If you do in fact go with those Delta monsters, make sure you get longer screws at your local hardware store. The ones which come with the H100 aren't long enough for a 38mm fan.
I ended up setting my H100 to the lowest performance setting in order to make my Delta's into something I could live with. They
DO have awesome static air pressure, thing is my system didn't exactly run very hot to begin with. The H100 is actually quite adequate with its stock fans.
It's just that I've come full circle to where I was about 10 years ago. I now have 3x computers for various different uses, and I just wanted the best possible cooling for my gaming rig that didn't involve ging to a full custom loop. Noise isn't such an issue for a gaming rig as you've always got your headset on, however yes, you can hear the fans through the headset.
The Delta's are awesome just to play around with, along with the fact people ask whats in the rig. Take the side off and there are two nice big fat fans with wire grilles on them, look pretty tough ;op
EDIT: I'd be concerned about that 150CFM fan you linked to. It has the potential to blow your mainboards fan headers. The 253CFM fans don't have that issue due to having 2 pins for PWM control and a separate connector to draw power direct from the PSU.
Ah cool. I didn't know there was such a big difference between the H70 and H80. Now I'll have to make up my mind if replacing my NH-D14 is worth it...
Not really mate. I don't think there's any reason for you to replace that cooler at all. It's still one of the best on the market.