No offense, but the unmasking of Vader is SUPPOSED To be disappointing. No human(as evinced by the Emperor's lack of armor/mask) is going to WANT to be like that all the time. He is a damaged and not completely formed human.
Sebastian Shaw had one of the kindest, warmest faces(which you can see even in the makeup and definitely as he appears at the end as a ghost) and that hack Lucas edits him out of the DVDs for Hayden Christiansen.
You also must have missed Empire Strikes Back where Vader is in his meditation chamber and you see his helmet being put back on and you see a damaged and white head. pay more attention next time.
I agree on not killing the Emperor, but I think the idea is that Luke can't kill him out of anger/hatred and that Luke is actually already dangerously close to making a "bargain" to save his friends(and father) Any move to killing the Emperor draws HIM closer to merely replacing the Emperor(or Vader) It's not that killing the bad guy is always an evil act.
Even worse, that dork Hayden Christiansen (who I expect to once again be the weakest actor in the new installment) has a sinister leer on his face in that final scene. While Yoda and Ben Kenobi look on lovingly, Young Anakin looks like he wants to rape you with his lightsaber.
Why does the unmasking of Vader have to be intentionally disappointing? Is this your own personal read on the story? But since art, or at least Star Wars, is subjective, I was hoping for a more extreme visual. I think Mr. Shaw's kind, warm face is a matter of taste. Personally, he looked like a pedophile piano teacher.
And NO, I did NOT miss the part in Empire where we see Vader in his meditation chamber. I don't even know why you would even assume that I did. Empire is one of my all-time favorite films. In fact, the back of the head seems much more scarred and damaged in that film. I was hoping for something a little more extreme in the third film, instead, we get a slightly bruised and pasty, second-rate Sontarian Warrior look alike.
No offense.