Hmmm, I dunno really. The matallic was popular in the late 80'/early 90's and then it died down again, even thought they launched a pearlescent.
I know that the BRG metallic is a real ars3 when it comes to longetivity. In my experience, when looking at cars that are a couple of years old, it shows every scratch and if you run the car through a car wash then it will show the swirls forever after. Along leading edges, e.g. top of wings, roof, top of doors, etc.
The other half had an MGF abingdon which was Brooklands Green, not met or pearl and this seemed to be O.K. although this is probably an unfair example as the previous owner had bathed it in milk to wash it, etc.