1903-O 10C MS66+ Certification #06666237, PCGS #4831
According to the PCGS Population Repor, the 1903-O Dime is slightly more plentiful than the 1903, but not nearly as common as the 1903-S. Among Mint State 1903-O Dimes, collectors are most likely to encounter an MS64, though MS62 and MS63 examples are also common. In MS66, the 1903-O Dime is a significant condition-rarity, and MS67 appears to be the highest onbtainable grade.
The strike quality of the 1903-O is exceptional, nearly on par with the Philadelphia Mint issues, and far superior to the O-Mint products of previous decades (the horribly weak 1890-O Dollar comes to mind). In high grades, eye appeal becomes a significant component of pricing, and beautifully toned examples will command large premiums.