I've had a look at GM's first edit of the Vader-Emperor convo and didn't think it was a bad compromise. I can see why there's a question over Vader repeating 'but he's just a boy' when the Emperor has already said he's a boy, but you could interpret that as Vader trying to come to terms with the fact that Luke would be as big a threat as the Emperor is implying. The interruption works well, but as said, the musical ending to the first edit was a little overpowering. However, having seen the second edit, it now seems that there is something a little lacking when he bows his head, as if there should be something to end the scene. Didn't the original one have a drum timpani ending to the scene (like a dum-dum type thing)?

On the subject of the Emperor, I'd like to see him clouded in a little more darkness. It's all very well seeing him, but I preferred the Emperor to be a little more mysterious. The 2004 additions were almost an exclamation of ILM saying 'Look what we've done!' (along with a lot of the additions they made).