I remember having an altercation with my English professor about this very issue. He was a good teacher and he was probably right to prefer "got" to "gotten" in the context we were discussing, probably an essay I had written and was trying to defend. I said, "Well OK from now on it's "Moon for the Misbegot", "His only begot son","While I pondered weak and weary over many a quaint and curious volume of forgot lore." Alas, I have forgot(ten) how he responded.