I am not understanding why people care either way whether its a turbo I 6 or V6 engine. To be honest I am willing to bet almost nobody would be able to tell a difference if they did not know which configuration it was just by driving it.
The main dilemma for people is preferring a NA engine over a FI. However once you go FI, it really does not matter if its inline or V with turbos. Both will have the exact same feel with the V6 likely being more smooth with less lag given its configuration being condusive to bmw's current turbo setup on the m5.