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The 'Bring me my shuttle' line is a controversial thing. How do we know that it's already there? We don't know that. Perhaps he had it sent up back to his stardestroyer on the far side of the system to hide any kind of imperial presence on Bespin. Fact is, we don't know. It's just a matter of viewer's off-screen imagination. My main reason to revert back to the old line is consistency of sound. The line they used to replace the old one, was taken from the dialogue archives of epIV so it doesn't really 'go with the flow' as Vader does sound entirely different (even though it's the same actor talking).
Another thing is, that that line kinda announces what will happen next. Redundant informations like that always get on my nerves, because it makes me feel like LFL thinks I'm too dumb to add 2+2 together. I don't need to be told everything twice. I want a fast paced movie. And that elongated scene/dialogue always seems to hit the brake on the action for me. In my eyes it's like a double post on a forum that no one cared to delete.
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When it comes down to the rings in the blasts in 'A New Hope', I never thought they were a huge improvement. In fact it made it even more boring because every planetary body (Alderaan, DeathStar I, DeathStar II) all had that same effect, same color, same extension speed and above all: 2 Dimensional. The only time it really felt like an improvement to me, was in RotJ since I was never quite satisfied with the cartoony look of that explosion. So for the sake of keeping that effect addition fresh and unique to me, I only left it with the explosion that looked the most boring to my eyes in it's original form.
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Edit: The Dianoga thing is just a first reaction to the screenshot I saw of it, eventually I'll leave it in there. Alas, at this moment I'm really bored about yet another monster with 'cateyes'. That's really all there is to it for me.