Look at his sig, "Cast Plenum (prototype), Headers, High-Flow Cats & X-Pipe (prototype)", Buff is connected.
Like I said, it's been beat to death.
Here is one thing to consider, the Nissan plenum is designed to flow air down the both sides of the plenum, not over the top as Crawford claims is their reason for the large front.
Another thing to consider, there is no reason the plenum needs to be as tall at the front as it is in the back because all the air comes from the back, so 66% of air needs to pass by the back two cylinders, only 33% needs to pass by the center two cylinders. I don't specifically know about the cast plenum but the v5 gave no greater volume to the back, where all the air is coming in from, while the motordyne spacer adds more space in the back as well as the front (this is not true for the slanted AAM spacer).
Finally the "only 150 more" is just for the plenum and not the strut bar, and for those that got in the the group by represents a 100% increase in price.
Chris