It's almost the most expensive out there but i think it deserves the extra money. Its installation is very easy (everything is included). There are some very specific things that are worth mentioning.
First of all it has a angle at the beginning of the plenun where the TB is located.
Apart from clearance issues as you read, this angle serves for better air flow at the first cylinder which is a common drawback of stock manifolds.
Some pictures of itHONDA
PERFORMER X (3000-7800 rpm)
The Performer X intake manifolds for Acura and Honda’s are engineered for street/strip applications where peak torque and horsepower gains are realized between 3000-7800 rpm. The larger-than-stock plenum volume and 9" runner length are tuned for producing peak power at high rpm. The Performer X Series manifold is ideal for all-motor and turbo applications. May be upgraded to an eight injector system by purchasing a #4779 secondary fuel rail kit and drilling through the partially machined secondary injector bosses
Here is a good write up for this manifold. Tested on a stock d16y8. It scored almost 6 more hp with emphasis to high rpms.
http://importtuner.automotive.com/64346 ... index.html
Here are some more pics from my engine bay
Here you can see the distance of the plenum from the firewall.
I think the runners are longer than the skunk2.