Different ones in the E89, originally fitted with the 6 speed auto box and the 7 speed dual clutch in the 35i (option) and 35is as standard. The newer models since 2012 have been fitted with the 7 speed dual clutch (35i and 35IS)and the 8 speed auto instead of the 6 speed.
I never had any issues in my E88 with a 6 speed apart from a software issue which was promptly sorted, my mum has a E61 auto with the 6 speed again no issues.
What model are you looking at?