Mike, you are comparing my stock block 04 DE dyno to a 370z dyno (because no DE has ever made 276whp on a base run) Not sure the boost on that run either. Thre is almost a 10 year time laps between these two engines.
I also think that install cost should be thrown in the mix as well, not to mention ease of maintenance. It is not just a $500 difference, and I am sure many would agree.
It would be silly to get in to an argument over the two systems, as they are very different, and each have pros and cons.
EDIT:
I think this would be a much better comparison, as the engines are the same and boost is the same:
91 Octane fuel, 9 PSI, with a temp. manual boost controller:
Specs on the build aboove:
GTM Stage 2 Turn-Key Twin Turbo System
Cosworth Intake Manifold
Cosworth fuel rails
600cc injectors
GTM ECU Flash
Upgraded MAF Sensor
GTM 14" Fan kit w/ fan controller
GReddy EVO TT Exhaust
S.S. Braided vacuum lines
GTM 3" Down pipes
Defi Gauges
Credit the Cossworth IM for carrying the power better in the upper RPM's.
SOURCE:
http://my350z.com/forum/shop-builds/...p-413rwtq.html