I don't think anyone expects him to be age 30 Trumbo bad. I also don't think anyone expects him to hit 47 homeruns.
As for what he's done? ¯\_(ツ)_/¯
I can't translate AAA stats into ML performance right now.
He's probably an above average hitter and a below average fielder. How much of each is anyone's guess.
I'm not expecting three to four win seasons on the regular.