http://www.clunk.org.uk/reviews/noctua-nh-d14-premium-cpu-cooler-review/Page-6.html
If you scroll down to the chart, if you take the Noctua cooler with 2 120mm fans (54cfm noctua fans) and compare it with a mega at the same 2 fans, their load temps are exactly the same according their research.
They show the cooler with 3 fans. So then you have a push-pull/push-pull setup. That may change temps a small bit but its the same diminishing returns as adding another fan, then it won't be much. For example, you take the megahalem with 1 fan and add another fan, the temp difference if 1-3C, if you were to somehow be able to add a 3rd fan, its temp difference would be .5-1.5C from having 2 fans.
Still a good theory to test.
I got a feeling that since from graphs i seen in these 2 threads of TRUE vs MEGA, the mega works way better with medium and high fans, so it would still be good competition for the noctua cooler. True on the other hand would still hold its own vs the other 2.