I know this isn't really helpful, but I will say that, before I bought our XC90, I was considering an X5 that had massaging front seats. I didn't ever test drive it, though. From what I read, the massage feature is aimed at keeping the legs from stagnating (or stiffening) during a long drive.
Had an X5 with the active seat. It would move your butt and spine back and forth. It was amazing. Every other car a 3 hour trip to the beach, my back would hurt. With the X5 I drove from Virginia to Florida a straight 14 hours and no pain.