I find the handling to be excellent just like being on rails, no problems whatsoever even at speed. I was unaware the Police has gone for the xdrive option? Certainly not seen any in use yet in Essex, same goes for 335d most Police cars seem to be 330d. I can understand the additional training if you have been trained to handle RWD at speed etc as the characteristic are very different. The grip stays constant where with RWD at speed there is a point where it will try and let go. Personally very happy having had 535d's in the past this is certainly a good step up from a handling point & over 40mpg is a bonus.