The meaning is different.
You talked longer than him. You made a speech that was two hours longer. His was only one hour long.
You talked more than him. You were having a conversation with him, and you had a lot to say, and he made only a few comments.
I'd prefer "You talked longer than he did" and "You talked more than he did." But they're both okay.
I hope this is clear.
regards
edward
Which is right? " You talked longer than him" or " You talked more than him"?