I do OCR RS and it's split into 3 different papers; Philosophy of Religion, Ethics and Developments in Reiligous Thoughts, with 4 forty mark questions and 3 being answered for the exams. I think what seperates RS from Philosophy is the added religion component and your studying the philosophy of religion, you'll be learning about arguments for the existence of God, the problem of evil and etc. One thing to note is that in OCR philosophy of religion, the 1st topic is the Understanding of Reality, which is not a topic is AQA RS.