Is metal better?

The last years, there has been a clear trend within consumer electronics: The devices must have a smooth metal surface. This is perceived as a mark of quality: Metal means solidity for the general public.

One example is the Lumix G 12-32mm f/3.5-5.6 (my review) pancake zoom lens, seen below (to the left) compared with the older Lumix X PZ 14-42mm f/3.5-5.6 (my review):

Lumix G 12-32mm f/3.5-5.6 (left), Lumix X PZ 14-42mm f/3.5-5.6 (right)

The older black lens has a plastic body, while the newer silver lens has a bare metal surface.