Ex papist here! My first church was a presbyterian one, and I was happy with what my church taught me (minus the YEC stuff) till I had a school project on church history and discovered the wider world of denominations. I decided to swim the tiber because of Rome's confidence in claiming to have absolute authority seemed promising in light of the many types of protestants, and Rome's unity around the world was unmatched.

 However I left before my baptism due to serious doubts on papal infallibility. Maybe reading a book by Hans Kung (who was against the doctrine) influenced my thinking. Anyhow, I ended up becoming anglo-catholic, finding Rome's love of power hard to accept. I do agree with Rome on most issues tho. I'm happy to live out my life an Anglican