My recent experience with the deisel X5 is good especially on sand. Used it on Fraser and was better than my last 100 series. The auto is great with the torque stopping "bog down" in the sand. The journo also rate the latest X5 as excellent on sand. Had it in Kakadu mid year and got thru the Jim Jim road without dramas though I cringed at the corrigations. Not nearly as good on rough/rocky stuff but will handle most normal dirt road in comfort.
Good luck with you choice - they all work and I suspect the real differences are found with driver skill and stupidity levels!
