Imo the top air coolers (DH-14, V-X and Megahalems) are probably within a few degrees of each other with a standard config such as using a single fan. Just pick the one you like 
I think that the Megahalems does better though at low fan speeds such as below 800rpm because of the design.

I think that the Megahalems does better though at low fan speeds such as below 800rpm because of the design.