Well, to address your question specifically, CFM's (airflow) is a function of filter media, surface area and proximity to the vacuum source. The pods on the manifold will flow more than a filter tucked back in the airbox, but to concur with the above statements performance has a lot to do with jetting.
With the right jetting, there's not much "seat of the pants" difference between either filter. You may have some high RPM gains with pods and low to midrange with the box filter.
Now that box is a Helmhotz Resonator, but that's another story.