There never were problems with the black finish flaking off, because it's never BEEN a black finish.
It's entirely black plastic. What was flaking off (of THREE machines that I ever heard of) was probably a little excess separation agent from the mold.
Aside from that, my reasons for going with the black option, in order:
1. The matte black is MUCH nicer to the touch (I *really* don't like the feel of the white MacBooks).
2. The matte black, for some reason, is MUCH more scratch-resistant than the white - most scratches will actually rub right out when you just rub them with your finger!
3. The black, while it smudges, always looks cleaner and nicer.
