Glos Guy, I have the sport seats in leather, the adjustment is back tilt, seat base also as a tilt adjustment, up and down adjustment, the front of the seat also extends to support back of legs, my wife loves that, she as long leg’s, their’s also a button which pumps /deflates the side bolsters. My seats doesn’t have the lumber support fitted it was a cost option at the time.
My X1 is now 3 years old so I don’t know what /if changes have been made.
Hope that helps.