The 1901-O Dime is not a particularly rare coin, but it definitely commands a premium in most grades when compared to the normal Barber Dime "type." Mint State examples are fairly plentiful and appear most often in the grades of MS63 and MS64. The best examples are MS66, with one or two finer.
The strike on the 1901-O Dime is generally good, though weakness can be seen sometimes on STATES and OF on the obverse (either the entire words or a few letters in each word). The reason for this is unknown, as the same coin will show strong details in the wreath on the opposite side of the coin. Perhaps the obverse die face was slightly out of parallel with the reverse die face.
In any event, this is a great date in a very popular series.
Bob R. Simpson Collection - Legend Rare Coin Auctions 12/2014:87, $4,583 - Srotag Barber Dimes
Heritage 2/2007:2945, $5,750 - Heritage 8/2011:3630 - Lily Nicole Collection - Heritage 4/2015:3927, $3,700.07 - Heritage 12/2015:4248, $1,997.50