In all honesty the 65 grade should of held up at PCGS, 65 grades are notorious for poor margins, also 64,s tend not to have that issue, now if you compare the 66 to the 64 and 65 grades the margins are much better.
Was curious since you have them in hand what your thoughts were. So it seems at least with your group that PCGS was more conservative with the grades? Not all of them are showing for me either.