One of the fruits of this consecration? A vocation to the priesthood.

The Virgin also helps me to grow in humility, purity and faith.
If you look at JPII you SEE the fruits and its effectiveness.

It will take more time though to explain why exactly! Maybe one thing: Mary, blessed among women, is
the woman who will crush the serpent’s head. (Genesis 3:15) Why did God want it to be like that? Saint Grignon de Montfort suggests that for the Devil to be defeated by a simple woman is much more humiliating than to be defeated directly by God himself. It is like Goliath and his mighty army being blown away by a little shepherd!
As Mary says herself in her “Magnificat”: “The Mighty One has done great things for me … He has shown might with his arm, dispersed the arrogant of mind and heart. He has thrown down the rulers from their thrones but lifted up the lowly.” (Luc 1:49-52) The strength of the devil is pride. God conquers through the most dazzling humility. He has a sense of humour!
Our Lord did not have to associate the Holy Virgin in his plan to crush the serpent’s head, but He did. He can chose to do whatever He wants. Mary is nothing in herself (as Saint de Montfort states!) but thanks to God she is full of grace: “gratia plena”! Now: how full is full? What is fuller than full?