I thought that my 2008 ASE was the prettiest coin I'd ever bought from the Mint

Alas, I got the grade this morning. PF68UC. What did I miss? At least my 2007 ASE got a PF70. That's a not-so-small consolation. When the coins come back to me, I'm going to spend a lot of time looking for defects on it. I also wonder if it got a low grade due to the fact that there isn't yet a large number of examples to form a decent baseline. I'm thinking that I may just wait a few months, and then ask them to re-examine it.