Originally Posted by X5SND

To answer that accurately you have to take into account a couple things.....

How much are you looking to spend? how many miles on the current dampers? What are you willing to sacrifice in terms of height vs ride quality....there's a ton of info regarding the different lowering spring sets available.

IMO if you have anywhere in the neighborhood of 80-100k on the X then you might as well do dampers and springs.

There's also a ton of info floating around in terms of the effects of the various spring & damper combos and what they do in terms of ride.