The 1928-S in scarce in higher circulated grades and quite rare in mint state. It is definitely one of the key dates in the series in Gem condition. The 1928-S is a little rarer than the 1927-S, but not quite as rare as the 1923-S. Strike can be a real problem with this issue and there are many mint state specimens that are very weakly struck on Ms. liberty's hand and in the central eagle's feathers on the reverse. Even a decent strike is very rare and I cannot recall seeing an example that I would call well struck. Luster can be white and somewhat frosty, but toned mint state coins seem to be in the majority.