I'm no expert, and I look forward to learning more when others answer.
I assume this is a 2006-W with a Burnished Finish--is that correct?
The Official
ANA Grading Standards for
United States coins says that PF-68 coins have no more than four lightly scattered 'miniscule' contact marks or flaws, none in the focal areas, and "no spots". The last point might disqualify your coin for PF-68 and move it down to PF-66 ("one or two tiny spots at most") or PF-65 ("A few spots may be present, but they do not greatly detract from the overall eye appeal.")
So my conservative guess would be PF-65, but I for sure defer to the experts for a more definitive answer!