It is an aftermarket ECU, best used for a heavily modified engine. The ECU is fairly cheap but you would need to spend at least 1.5 times the cost of the ECU on mapping it correctly.
I have a DTA ECU on mine, and it has taken a year to get full mapping, and it is still not perfect, so it goes to show how much mapping is involved.
The performance potential is great, though not on a standard engine, as you may only see a small increase in performance, but fit cams, throttle bodies and the like, and it would have a great effect on performance. It releases extra performance by having it mapped for performance rather than economy/emissions of a modern OE ecu.