Ron Guth:
Though the 1903-S Dime has the smallest mintage -- by far -- of any of the 1903 Dimes (Philadelphia, Denver, and San Francisco), more 1903-S Dimes have been certified by PCGS than either the 1903 or the 1903-O. This may not be indicative of relative rarity, but may simply be a reflection of the higher value of the 1903-S.
Numerous, high-grade examples of the 1903-S Dime have survived, usually in MS64. At the Gem level, MS65 and MS66 examples appear to have survived in relatively equal numbers. The best example is a PCGS MS67, formerly of the Bob Simpson Collection, which ranks as one of the finest (if not THE finest) Barber Dime collections ever assembled.
The strike quality of the 1903-S Dime is excellent. Luster ranges from prooflike to a hard brilliance to a soft, creamy surface.