The huge torque in X5D is not that noticeable because of the weigh and slow shifting tranny, where the car lacks big time is in hp department and faster transmission/diff ratio. The 3 series diesel however is totally different animal you can really feel all that torque.
After I remaped my X, I can really appreciate the added HP not so much the TQ.
Retired: 2005 N52 E90 330i Sport 6AT
Retired: 2007 N54 E92 335i Sport 6AT
Current: 2012 M57 E70 X5 xDrive35D