Is game grading more accurate/knowledgable than say, card grading? Are they good at judging whether a seal is original or repro? I haven't really followed it, so I don't know.
Sports card grading (PSA mostly) is currently in the midst of a scandal. Large numbers of high-dollar trimmed and chemically-altered cards in high-grade slabs. The total percentage of affected cards may be low compared to their totals, but it's still ugly. I wonder if game grading will, in the long run, end up more like pretty reliable ol' CGC or pathetic PSA.