My few decades long experience with compact discs is... binary (no pun intended). Meaning, either it plays perfectly from end to end or it plays perfect until... we hear it skipping, jumping or "sliding" to the of the track or disc. This, regardless of any visible hairlines or scuffs. So these gradings are just visual gradings that can only be reasonably trusted if the disc is spotless or a minimal scuff can render a disc unplayable (as the expectation has to be that I can play it end to end). With vinyl by comparison, there's a continuum from a that rare flawless and silent playback, to a progressively greater surfase noise, to the odd "pop" but otherwise surfase noise only, to the cement mixer output, to the unplayble deep scratch. In sum and put in another way, why pay for a M CD when a cheaper VG+ should play as nicely? Maybe missing something!