Most of the tenths I have ever submitted graded lower than the singles and halves. I am not sure why or if I just had bad luck with the coins I purchased. MS68 is a really nice grade and should demand a nice price. I agree with when people get high grades they tend to sell them and take some profits. It really depends on who gets the coins though.
I'd love to be in the room when these ANACS folks grade a coin to see what they're really seeing, what they're discriminating between from one coin to the next. They all look so perfect to me, but obviously I'm not an expert.
It seems like a true statement that their could never be other MS68 graded coins like these in the future, especially given the small quantity in existence.
They use magnification @ 8x to grade the coins. I am pretty sure that is the standard used when grading. I have a direct line with Andrew at ANACS (he is not a grader, but has agreed to answer any community questions I present him with - he asks graders). I was going to make a grading thread here with example submission forms and take questions etc... - Guess I will need to motivate myself and get that done.