nightstalkerpoet said:

... Leave Anakin to die on Mustafar.

Padme's funeral.

Yoda goes to Dagobah.

Emperor/Vader/Tarkin looking at the death star (change that to be Coruscant or something else)

Roll credits.

We lose... NOOOOOOO! and the scenes with the twins. Secret, for the most part, preserved. Where's the cool stuff?

Not showing that Anakin lives, and showing Vader at the end even adds to the deception.

ABSOLUTELY THIS.

I too would like to know what "cool" stuff we would miss. However, if I lose cool in favor of substance, I'm going to choose substance every time.