Do you know what BU stands for?? Brilliant Un-Circulated and it stands for MS62/MS63/MS64....GEM Un-Circulated stands for MS65/MS66/MS67.... Speedy
That's how it is defined in the Red Book Right? Here is the thing, there is a huge difference between a 63 and a 64 in both value and quality of the coin. 63's in many coins are a dime a dozen. Ruben