My experience with my SW update... I believe BMW has come out with a de-tune that gets rid of all these strange sounds the N55/N54 makes... but in doing so they also have "neutered" the car's performance (balls). 90% of consumers probably like that. I do not! I think it saves them from (clueless) owners bringing their cars in for service with these "sound" and "driveabilty" complaints. And probably saves them from buying back some cars too bc of those said noises.
Post SW update, my car was quiter, idled lower (and smoother) had little to no injector noise at idle, no wastegate noises and "felt" smoother while driving. BUT... alot of the snappy performance was GONE>! Before you only had to press manybe 1/4 throttle to get ripping acell, post SW you needed to press down atleast 1/2 throttle or more.
I think some of "us" here have a good seat of the pants dyno(the Germans call it s "popi-sensor"!
)... while others do not. I really hate what BMW is doing to our cars. I will never have another SW update done.
All that said... I am glad there is an aftermarket... bc with my flash tune... my car is way better than before the SW. It has all those old glorious noises/rattles/sounds... but what I really like is the car just rips now at very low throttle. And when I do go WOT... OMG!!!
Dack