On the VF-1J M&M, when you pull the chest plate down, it's very easy to scratch the two white tabs that stick up from the back. Mine came with a little piece of paper in Japanese that pretty much cautions you about that. Basically on the VF-1J M&Ms, the white paint is very soft and easy to scratch.
The new 1/60 Roy VF-1S is supposed to have the fixed post VF-1D v2.0 shoulders.