Trying to understand Manifold choices

The next best option was the L3d (spelling?) and the RPM Air Gap, both flowed just as good or just bit better, and definitely much lighter.
So I am trying to understand why would someone install a plain Performer intake over the stock intake, it has to be only because of the weight and or cost. I don’t believe that it flows as well as the original intake!
Weight savings over the iron. Plenum style. We are about to put a Performer on a Barracuda's 340. That was chosen over the Air Gap due to the climate being more temperate and the car is driven when it's pretty cold out.

I love my LD340. Great for a cruiser or mild street/strip.