I`ve mapped quite a few cars on the Airtec top feed cooler though, and even at over 36psi on GT30s the Inlet temps were only a max of 5 degrees over ambient on the dyno, most of the time the were only 1-2 degrees up on ambient and thats sat on a dyno run after run after run while mapping.
Thats far from bad so i dont see what all the fuss is about. The cheaper one works really well and i wouldn't hesitate to fit one to any car.