For anyone reading this thread who does take their X5 into sand: The key is to turn OFF the traction control. We run ours on the beach fairly often, and you need some wheel slip to get through soft sand.
With traction control off, the X5 is no better, and no worse, than the XC=90 and Grand Cherokees we had previously.
2014 535i MSport Space / Black, ZCW, ZDA, ZLP, ZLS, ZPP, H-K and 704
2015 X1 28i xDrive Alpine / Black, xLine, ZCW and Ultimate
2015 X1 35i xDrive Black / Black, ZCW, Ultimate and Xenons
2014 328i SportWagon
2011 535ix MSport
2011 X5 35D
2008 ///M3 Vert
2008 X5 3.0
2007 X5 3.0
2006 X5 3.0
2006 550iA SP
2003 540iA M-Technic