Obviously the flaws of the third part are too many, and also discussed extensively. But here are some of the good ideas in part 3 (in no particular order)

1)Kay visiting Sicily
2)Don Tomasino
3)Flashback scenes of apollonia (and the recollection of women in michael's life)
4)Connie getting involved in the business.
5)Kay's thoughts that she was still in love with micheal though she dreaded him.