Yes the colder the air, the denser the charge = power is true. But , the longer the pipe and the greater the volume to fill, the longer the time taken to reach piston = slower engine response time (note I did not say anything about lag).
Turn your hose on and see much longer it takes to fill a 15L bucket Vs a 2L one at the same hose pressure, thats the difference in volume between the GTR cooler and the stock gtst one from memory. Sure the air is colder and the engine makes more power, it just loses time in getting to the same rpm.
If you'd like to tell me how making the air path 'longer' increases performance I'd be interested to know too.
I don't think you are suggesting that making the intercooler pipes do two laps around the car body would help. The principle is the same on the larger volume intercooler although the magnitude is less ridiculous.
You may be missing my point. The 'power' over a stock unit I have never disputed. My issue is the possible response time issue introduced by the greatly increased volume of the new intercooler and piping.
Here's how I back up my claim alternatively :
Let's see a front mount intercooler equiped R33 gtst with a stock turbo run better than a 13.3 @106mph on 205's. To the best of my knowledge there isn't one.
I'm not trying to poo poo aftermarket intercoolers, I'm very sure that you can do much better than the stock unit, it's just that for the extra expense you need to make sure the size is 'just right'.