Ind. kits generally suffer from what's known as 'heatsoak'. They get hotter than the OEM airbox due to the engine bay temps., & as colder air = more power, this is bad. (On a cold day in winter, though, they MAY be better).
IK's definitely sound better, though.
The OE airbox has plastic 'flaps' left inside it from the moulding process, so cutting these out & then smoothing the inner surface increases the airflow efficiency.
The R32 DSG intake is bigger than the stock item, allowing more air to be drawn into the engine = more power.
TIP = Turbo Inlet Pipe. These don't bend on heavy load from re-mapped cars like the OEM item does.
