Oh my. The rewards and benefits are endless. You don't need to physically look at the text to pray because you have it in your mind. You can pray on the go. That's the main benefit for me.
Becoming a Hafiz is fantastic, my only advice is that they need to sit down with the children who want to become Hafiz and explain that it's a life long commitment and that they must remember it for life. It's not just a "complete it and it's done" thing. I was never told about it when I started and when I found out half way through, I wanted to pull out but I was not allowed. :hiding: