Why do you think Sony V6s made in China suffer from poor Q.C. or poor build quality?
I tried on a V6 in some electronics boutique shop in the mall that
closed down early this year. When I played some tunes I noticed right away (before noticing that it was made in China... of all places) that the there was channel imbalance, ear cups looks scratch-prone and the wiring that goes from the earcup to the headband is of really, really low quality (cheap ass rubber-like wiring that looks cheaper than a iPod earbud white-colored wires) and I doubt it will last more than a decade (I mean c'mon... V6 is known to last a decade or two... or even three!)
Then I went to Guitar Center and tried on some Made-in-Thailand 7506's. The build quality of the 7506 is such that it highlighted the glaring quality differences with the V6 I encountered in the mall.
Because of this, my takeaway is:
1) V6 that I encountered in the mall is legit, but is made in China with QC issues.
2) V6 that I encountered in the mall is a Chinese fake.