I've run an E60 535d for four years, now on an F10 535d.
If you've only driven a 530d, then you would wonder why bother with a 535d; but once you've tried a 535d, you wouldn't want to go back.
The two things that really set the 535d are instantaneous throttle response - there is no lag whatsoever, it is sharper than even a 550i - and the ingear acceleration between 30 through to 70 - passing slow moving traffic becomes so easy.
The price difference isn't quite as large as it seems, as the 535d has the auto as standard.
On it's way G30 540i xdrive
F10 535d mSport 2014
retired : F10 535d mSport 2010:E60 535d mSport 2006: E60 535d mSport 2004:E39 530i 2001:E39 528i 1997