its a great bit of kit and works well as an additional piece of the jigsaw for maximising your returns when it comes to a remap. Abbey seem to like them as they buy them as well. as do a few other places. its never going to be a magic bullet that suddenyl produces 100BHP form no where (we all know the car is notoriuosly had to squeeze anything extra out of NA without a remap).
Flyboy produces and sells these they are a supurb piece of kit, the fit and finish is excellent, the instructions are a doddle to follow. they make an improvement on the the stock car and if you have a pre 2006 this should be on your shopping list to fit to your car. and at £36 you can't really go wrong.