Given that the same model can run differently, and that most of the metal is the same, it does suggest that the ECU for each model, was commissioned in batches, and then maybe tweaked on the quiet when issues emerged like rev hang and the GDI fast rev up from cold. MMC sent an ECU upgrade to dealers for the GDI to soften that intiial revving. So unless you check the label on your ECU, against other cars, there is no way of knowing what changed. The hair trigger throttle I had from new made it very hard to set off smoothly, but not all GDIs had that, and it makes no sense.
