Di Vaio seemed the best of the lot and I couldn't understand why he was in lower pecking order to Corradi (yuck!) when Ranieri was still around. Even then I thought he was the best of all four new Italians. His little time in the match against At.Madrid was impressive although we lost and he scored a wonderful goal in Mastella against Getafe. Moretti hadn't much playing time since Ranieri left but he was okay then and could improve as time goes on like D.Navarro (if he gets more chances). Fiore scored 2 nice goals this season but that's about it, less playing time than those three. I already commented on Corradi in the bracket above.
Ranieri wanted to build a team with Italians, He was sacked and the players were unhappy. Di Vaio's been pretty good, but Fiore had problems imediatly and couldn't adapt. Corradi was so so even in the past and Moretti was a wild guess since he was too unproven IMO. It's likely they all goes back to Italy next season anyway.