Ok this is nothing I havent said before:
The ECU makes the car much easier to drive in traffic. It is much stronger off the line on both crawl-away and hard launches.
The car is quicker in every situation now. 60 comes in around 6 seconds (tested twice with 50 miles of fuel in the tank, 2 people in the car, and a Ericsson phone stopwatch).
The engine feels much stronger at 7,000 rpm where as before it felt like it was struggling to go any further. 8,000rpm equates to ~40mph in first.
The car is still averaging the same mpg figures (around the 25 mark for me). I rate the ECU very highly and thought as R-Sports first ECU customer Id let them know. I phoned them that night to tell them I was very happy.