I've owned BMW's with torque vectoring (X6)...I'll guarantee anyone if you drive and X5 with DHP right with an X5 w/out DHP - you will notice a substantial difference..
That said? $4500 is a big chunk of change and its entirely subjective as to whether it is "worth it" or not
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Previous Rides: 535xi, M235xi, X3, E92 M3, E70 X5 35d, X6 50i, X6 35i, E60 550i, E46 M3 Cabriolet, E39 540i, E36 328i