Had an alfatune remap, dpf, egr blank and it made very little difference to car. In fact car smoked white when cold and bellowed out black smoke when under load. Neither Gus or Alfa specialist could fix it. They replaced the airflow meter which made no difference and eventually seemed to be guessing what parts to replace at my cost so I had car returned to standard. No hard feelings as they gave me the remap refund but obviously out of pocket with the 2 rolling road sessions, air flow meter and the fact that I want the EGR DPF remap benefits on the car.
There is still a few months on the warranty left so hopefully the dealer may get to bottom of problem and then i was thinking I might go to angel to get the remap etc.
I agree that all rolling roads are different and that depending on the mileage and age of car the figures will difer. You can sometimes get to identical engines and one will be quicker, more powerfull than the other but I have had cars that not only match the claimed figures they sometimes exceed them so imo 20bhp or more difference is a problem.