I did my upgrade to the Thermalright R600 VGA cooler. While I had things out, I determined that the Swiftech MCX159U cooler was too large to effectively mount on top of the DFI NB cooler.

Then I looked at the Noctua cooler I had, and it will fit IF you have a Thermalright 120 Series cooler and IF you orient the cooler so its flat face is pointing to the top of the case.

I think the Noctua cooler would also work around something like a Tuniq Tower 120, but again that would be IF the cooler was oriented so that the fan pointed towards the top/bottom of the case.

What I did instead was mount my fans at the top/back of case so they are bringing cool air into the case, and then flipped my PSU so its 140 mm fan draws warm air from the bottom of the case.

I also used the DFI copper plate sandwiched between the CPU and HSF and mounted the Transpiper assembly off the PWM at the back of the case.

Doing this has reduced my load temperatures in Prime95 by about 5 C, and my idle temeperatures have dropped by about 6 C. In addition, my PWM temperature is now about 12 C cooler at idle AND under load.

So, all in all, I am pretty happy with things as they are, and will no longer worry about adding an "extra" heatsink to the NB.