BMW 540i X Drive

[Icehanger]

Been looking at one of these and my first possible new car in a long time.
The dealer currently is unable to get hold of a demonstrator for me but let me have a 4hr test drive of a 520D touring which was great and will suit the family fine.

Anyone have an experience or own one? do they have a bit of sparkle to them or simply just faster than the 520D
I'm holding out for a drive of one and dealer is genuinely trying to get hold of one but thought about just ordering once happy with the deal.