Ron Guth: Experts have identified two major varieties on Proof 1976-S Eisenhower DollarsL
Type 1 - Thick letters with squared corners. Tail of S extends upwards, with the tip of the second S of STATES level with the bottom of the middle serif of the E.
Type 2 - Thin letters with tiny serifs. Tail of second S of STATES on the same level as the lowest serif of the E.
According to the PCGS Population Report (as of July 2011), the two major varieties are of roughly equal rarity. Virtually all examples are Deep Cameos. None of the Type 2 versions have been certified above PR-69 by PCGS.