The 1910-S has long been considered a semi-key date in circulated grades, as have all 1909-1915 S-Mint Lincolns. The mintages of these earliest Lincoln cent S-Mints is considerably lower (with the exception of the key date 1914-D) than all of the Denver and Philadelphia issues. In circulated grades, the1910-S is about the equal of the 1913-S, and those two are the easiest of the 1909-1915 S-Mints to find in circulated grades.
In Gem full red MS65 or better condition, the 1910-S is far more plentiful than any of the other early S-Mints, though it is relatively scarce. In fact, you have to go all the way to 1930 to find a S-Mint that's easier to find in Gem condition than the 1910-S. This issue is usually found with a decent strike. The color on original coins is often more light reddish-brown than "red-red."