The Argument: Back in 2003 all four Alien movies received Special Editions that re-edited the films and re-intserted previously unseen footage, with mostly positive results. The theatrical cut of Alien 3 may have been an utter mess, with studio 20th Century Fox completely dominating first-time director David Fincher, but many fans were keen to claim that the Assembly Cut from the special edition righted many of its wrongs. Adding a whopping thirty minutes to the film, the cut puts a lot more focus on the religious fanaticism of the inmates of the prison planet setting. Why It Doesn't Work: The clue this isn't all it seems should in that this version is called the Assembly Cut; David Fincher was so burned by his experiences with the film that he refused to return to it even a decade later. So while the versions of the other films are fully fledged Director's Cuts, this is just another copy of the movie churned out by the studio machine. This is best evidenced by the fact that what could have been most interesting scene from the film, an autopsy of Newt, remained on the cutting room floor, due to containing allegedly extreme gore; the additions made were rather uncontentious and unimportant. Many of the touted changes are superfluous (it doesn't matter whether the quadrupedal xenomorph came from an dog or an ox), while removing the chestburster from the final scene creates a seriously less cool image.
