The AC fills in a lot of character details, gives you an opportunity to gain some exposure to the relationships between the prisoners and understand them better. It removes the super cheesy Queen burst reveal. This is all good content. The ox's dragging the EEV up the beach is a great scene. All the dialogue that has been returned to the BluRay version is terrific. There's so many good things that were omitted from the theatrical cut that should have been in there.
I'll tell you what a superfluous scene is. The last 10 minutes of 'ALIENS'. The movie should end at the point that Ripley, Newt and Bishop disembark from the dropship. The whole climactic Queen fight inerrupts the narrative that is being propelled at that point (no one as actually adequately explained how something the size of an elephant can hide amongst the vehicle's landing gear and not set off the warning lights in the cockpit.... really?)
So yeah, the movie shouldn't have the Queen aboard the Sulaco. It's a superflous scene (oh, it's a great one! I'll grant that) but completely unnecessary. You can watch the movie without that scene present and the ending is the same. Except Bishop is torn in half. Well, if Bishop had been human that might have been meaningful but Bishop isn't - so there's no change made by the time the credits role. All 3 characters get away regardless of the Queen's presence or not.
Is the Queen Boss fight at the end of 'ALIENS' a superficial scene? Absolutely! By any reasoning you apply to it, it doesn't change the outcome of the movie if it is present or not. Ripley, Newt and Bishop still get away from LV-426. Which is what the movie is ultimately all about -their survival and escape. By the time they reach the Sulaco, the movie is over. No Queen fight needed. Superficial to the nth degree.
-Windebieste.
