CAI also is better just by itself b/c it increases the flow of air (if it isn't restricted as above photos) and it uses the cool air if the intake pulls air from a cooler spot in the areas under the hood. Racing is just one aspect of having a different and better air intake. The stock filter is pretty inefficent and it has less area than the CAI filter does or so I'm told. I have not torn the two apart and made any measurements.
If air is drawn from the passenger side of the engine compartment the air is even cooler b/c of the absence of an exhaust manifold/header. Those are a few of the reasons to dump the OEM airbox. I did mine to gain use of the area for a second battery sometime in the near future. We all have our reasons and yours is valid too if you are in to racing, as I am not.