Tacchi is a decent player is a fairly decent player, and Appiah isn't that bad either, I think Appiah just needed some more time to adapt himself to Juve. It was a pretty big leap in his career after all, I think the essential weakness in Juve this season was the defense. Leggrotaglie, wasn't what he promised to be and Ferrara, Pesotto, and the cadre back there are too old, and too slow.
Hopefully whoever comes after Lippi realizes that the need for a generational change is now, and brings some fresh air to Juve's defensive side.
As for Davids, he was a good player as long as he didn't get mad at the world scream at the referee and get to the showers pretty early, I'm happy for the good job he's doing in Barsa.