Have you run the NA across a Dyno to see what kind performance increases your ECU achieves.
I have a na Haltech now and we have tested it with a completely stock setup . Horsepower gains are very minimal. If you have no intentions of changing from a stock engine bay I would not recommend replacing the ecu, Haltech is really designed to help people that are planning on adding components to push the limits of the engine to go faster in a more reliable way and to tune as you go.