Not sure about it.
I have got a 20%IV-2800 CP dragonite, who really is a bad prestiger. Gives only 100 XP when prestiging.
On the other hands side, i have got a 98%IV-150 CP abra, who is a really bad prestiger. It does not defeat the defenders, gives 0 XP when trying to prestige.
I tend to believe, that IV is not all what is neccesairy to make a good prestiger.