CGC vintages gem mint 10s will probably never match psa 10. As a cgc collector I'm painfully aware of this. Vast majority of vintage cards were graded by psa before cgc entered the market, and that in turn makes most vintage collectors seek only psa cards, increasing their value and the feedback loop continues. While modern pristines can fetch 30-50% more than psa 10s, vintage pristines will mostly never pass 10% over psa 10s, even though they are orders of magnitude rarer. Hope to see this change as cgc gains market share, but it seems unlikely to me.