It's a gem. Slabs are for making money for nothing - who cares if some opinion differs by a point or two? Q. David Bowers said the real truth: There are only Unc. choice Unc. and Gem Unc. AN oldtimer who has real knowledge of coins!
If you got more light on the coin in your photos, I may have gone for the + grade. That coin is a beast with a super clean obverse.
They must not be seeing many of these in that condition. I was going to give it MS65, as well. Compared to what they're seeing it evidently warrants that higher grade.