The system used is ECUFlash. You need to know what you want to do and how to do it if you are going this way. There are no magical gains like you see advertised. The tuning is done to optimize the ECU for changes you have made to the engine and systems that are beyond the broad learn range of the stock ECU.

If you want a little more power you need to make the existing systems more efficient. This would involve changing the exhaust manifolds to some with a much more even flow and then optimizing the rest of the exhaust as needed. The next step would be to work with the induction system and head porting for the improvements there. All of this work does not require any changes to the ECU.