I bought the car with the auto gearbox because we have an X5 with the 6 speed auto gearbox and, being slower and worse than the 8 speed (when the 8 speed works as it should), it do works as it should 99% of the time. The new one I'd say 50/50. If I tested the car with the auto (no M135i in Spain to test when I bought mine) I would have bought it manual for sure.
About the interior wear, this is how my handbrake lever, seats, and driver's window padded bottom look:
This one is quite difficult to see in an image...
