When he was Seba's age, Miccoli was doing the same Seba is doing now, and it happened in a much stronger serie A.
My opinion is that both are extremely talented players but none can succeed to perform at the same level for a big team. Both were in Juve and neither was given enough chances while in Turin. I can only hope to be wrong about Giovinco, but I strongly believe that his place is in the 2nd echelon of the serie A teams and won't really improve a big team.
I'd obviously much rather have him than Giac, for example, but I wouldn't really waste much time and resources to bring him back.