I've used a magnet inside the oil filter in my 1.8T for most of its life (at 56k miles now) except during break-in. Every oil change, I clean off the metal particles which are about same size as the diameter of a hair (a few microns likely). Under a microscope they look like shiny metal spheres. I've never found anything bigger than that which I'd call a "shaving" (which I'd define as a highly visible chunk of metal. I agree that if shavings are coming off the engine, something is wrong. I doubt shavings are being produced during break-in in a healthy engine, but expect that the micronic sized particles I've seen later are more prevalent at this time.