As a renegade Episcopalian turned Catholic, Newman spoke to me where I lived.
Also, since I was a history major, his statement "To be deep in history is to cease to be a Protestant" really hit home with me. I read 16th-17th English history, which had landed me right in the middle of the Counter-Reformation. It only took me 30 years to get the message . . . one of God's stubborn wayward sheep.
Another good book for Episcopalians/Anglicans thinking about taking the plunge into the Tiber is This is The Faith by Canon Francis Ripley.
He was the head of the Catholic Missionary Society in London, so he naturally gauged his argument and reasoning towards Anglicans!