How much have things changed in the decade since? The xDrive50i is not even the highest performance X5 available although until the new X5M hits it is the highest performance X5 available for the new F15 generation. It is roughly the equivalent in the model range of the X5 4.8is of a decade ago since an M model did not exist back then. In 2014 what this means is a 445 horsepower and 480 lb-ft twin turbo 4.4 liter N63TU twin turbo V8 powered 5306 pound monster that hustles to 60 in 4.3 seconds and through the 1/4 mile in 12.8 @ 109.
To put it another way, quicker and faster than every M3 produced prior to the last generation E92 M3. You could line up next to an E39 M5 at a stoplight and pull away while sipping a latte. That is how fast BMW's SUV's have become but notice that they have not gotten any lighter. This generation was supposed to improve in that area by a couple hundred pounds (according to BMW who somehow keeps overstating their weight loss) but when weighed it turns out it actually isn't any lighter.
Everyone will no doubt state this is very impressive acceleration and it is but there is one thing that old X5 4.8is did better than this new car. It went through the slalom quicker and pulled .83g on the skidpad to the 2014's .81g. It also stopped 5 feet shorter from 70 miles per hour.
Hey, as long as this one is faster that is progress right?
Source: Car and Driver