Newbie to the E60. 520i known issues (engine, electrics...)

[resunoiz]

HI! I'm a Z3 owner planning to change for a E60, specificaly a 520i.
I'm member of other BMWforums but unfortunately 520i is not a so-common car so maybe here I'll found some folks with that engine.

I know the most "common" problem of this engine is that is very slow but it isn't a problem to me (and for italian speed limits is way too much...).

I want to know if this model (2004, 6-cyl) had known issues, specific to this engine and/or common with his bigger relatives (530i, 530d....) , or if has problem with cooling system, silent blocks ecc ecc...
thanks!