Proof 1860 Dimes are among the most plentiful of the decade thanks to a large (for then) mintage of 1,000 pieces. Thus, 1860 is a great choice if you are a collector of Proof type coins. They are usually well struck, the overall quality is good, and the higher-end pieces often come with great color and eye appeal. The typical Proof 1860 Dime is PR64, but there are small clusters of PR65 and PR66 pieces that provide relatively affordable options. PR67 examples are rare, but there are more PR67 examples of this date than any other until the late 1870s.
Cameo Proof 1860 Dimes are four to five times as rare as non-Cameos. Deep Cameo examples are exceedingly rare, IF they exist at all.