We have it in our X5 and it's very good on long drives. It is annoying at first but after a few minutes you don't even notice it and it really relieves the muscles in your butt and upper legs.

The 7 series used to have it in both the driver and front passenger seats equipped with ventilated seats but the accountants realized they could save a few bucks and it was eliminated from the passenger's seat. They've just carried the same system over to the X5.