With regard to "Shas Pollacks," or people with unusual memories who seemed to have visually memorized the entire Talmud and were able to pass a "pin test" (see here) I had the impression that such people were always marginal. I came across a grave stone inscription from 1802, recorded in Rabbi Marcus Horvitz's Avnei Zikaron, his collection of headstone inscriptions from the Frankfurt A.M. cemetery:
Evidently this Rabbi Yehoshua Heschel ben Avraham of Shklov was a Shas Pollack (מפורסם בשמו בשם ש"ס פאלק). Judging by the description ("great rabbi" "expert in Shas, Posekim and the whole Torah") he was far from marginal or a חמור נושא ספרים (link).
Actually, I have a suspicion that this isn't saying he was a Shas Pollack (pin-test guy) at all. Falk (פאלק) is a Yiddish nickname for Yehoshua, and given that he lived in Frankfurt but was from Poland and such an accomplished talmid chochom perhaps his nickname was ש"ס פאלק, a sort of pun.