The issue is, and I have seen this on BMW, Jeep, and F150 forums...that people actually believe that a K&N filter, or a CAI, or some other cheap bolt-on product improves HP or 0-60 or top speed or whatever. They believe the marketing. Not just believe it, but die on the hill defending it. The BMW guys are crazy about that stuff. But nobody ever goes and actually measures the difference. Nobody puts in a CAI then goes to the dyno to check it out. It's always "yeah, I can feel a difference in acceleration...."
I really doesn't matter. Do whatever you want to your truck. I am strongly considering a Vararam only because it looks awesome.