In simple terms.
Pop Charger
Good for sound
Not so good for heat soak
As a result "claims" of slight power losses
RTCustomz Airbox
Returns the sound to OEM (Although can't remember what that sounds like as it was some 2 years ago)
Great for heat soak, as the plastics take longer to get hot
As a result "very slight" increase in power
Me personally, if I lost 2bhp because of heat soak, I really can't be fussed. If I lost 10+ bhp then I'd be worried. If you want sound, go for the pop, if you want to retain oem response and no sound go for the RTcustoms box. It's all about how YOU want your car to sound.
I will never get rid of my ARC Air Induction, it looks the nuts, sounds the nuts and erm.... isn't made of nuts