Yes, the efficiency of the factory GTR cooler is a well known fact - proven repeatedly on cars running well over 300kw at the wheels.
You cant compare the factory intercooler to the Trust item, the trust is an upgrade and allows for greater flow, but up to a point, the factory intercooler will do the job just fine.
That aside, I was actually asking Paul if he has any proven flow data on the capabilities of the intercooler that Just Jap sells, as I believe in terms of flow you will find it in the same league as the likes of the Trust upgrade.
I dont see the sense of slagging a product unless we have real data to compare