Media-Create and Famitsu both track substantially more than NPD does. NPD's extrapolation methods and sampling panels for non-tracked retailers may prove to be brilliant, but Media-Create and Famitsu are both closer to "full tracking". In addition, I also refer to the fact that we get substantially more MC and Famitsu data than we do NPD data, so from our POV the data we have is more holistic on the Japanese side.
NPD is as accurate as any other sales tracker is or should be (IE if you believe Nielsen numbers, box office tallies, and any other non-PR sales tracking), but both Media Create and Famitsu are more accurate.
I would never ever mention this because I wouldn't want people to go into an NPD thread and say "BUBU EXTRAPOLATION!!!", but DefectiveReject seems to have an anti-Famitsu vendetta and there is no justification for this. NPD, Famitsu, and MC should all be treated as close enough to be true for the purposes of our discussion.