Hello!

I´ve read the description of the "chip", so I can tell you it´s waste.

Waste of Time
Waste of Money
Waste of Material

Here it´s often called "Resistor-Tuning", I don´t know how you´re calling it in english.
It means to adulerate signals of the temperatur-sensor (called IAT) by a resistor.
There is nothing digital in this box, it´s only a cheap resistor.

It´s still the same waste - a cheap resistor in a expensiv package.
One time they call it "digital", one time they call it "analog". But it´s exactly the same.

It´s not easy to tune up a gdi. And it´s not cheap.
If you want much power it´s easier and cheaper to swap an other engine. For example the T4-Engine (200hp) from Volvo V40 fits.

But for real I don´t know anyone who tuned up his gdi.
One guy tested other exhausts, optimiced ecu, other fuel (a mix of gasoline and nitromethane). At least he had a car with abaout 143hp but not suitable for daily use. Finaly he stopped the project and sold the car.

Other question:
Have you ever cleand your air intake?
Most gdi are full of grime, have no more their "old" engine performance.
Just remove your throttlebody and airintake (anything before the cylinder head) and clean it.
You will be suprised how much power your car has.
We have a DIY, but it´s in german:
http://www.dreamcarisma.de/mitsubishi/workshop/1.8_gdi_bj98_selber_blastern.php