1 Series 120d Msport software update, a day to complete ?

[PaulCW]

Hi I have a 120d mSport from 2009, have taken to registered BMW dealer for a Air intake manifold, ok not cheap, 4 days so far waiting for part so say, they are now doing a software update, 5 hours so far , I am informed that the 120d can sometimes take a day to complete the full update, I find this unbelievable, I am told this is a common occourance on the older 120d's ?
I have had mercs and other cars that have had software updates at a couple of hours max.
But the X bmw Mech said on this model there ar so many componets that have to be updated ??
Really??