just a quick report had my e46 318 (n42 engine) remapped by Simon from emaps couple of weeks ago now and I am well impressed. The figures on paper almost didnt look like it was worth doing 12bhp, 20 whatsits of torque
but what a difference its made, the car is much more quiet and lively, mid range acceleration has a marked improvement and it will pull away rapidly from 80mph (tested on private road) off the line launch is much quicker.
Flat spots are gone and fuel consumption has gone from 35.6mpg to 38.2mpg and that giving it some down the motorways
All in all well worth it