Alien 3 is definitely not perfect. It may have a new setting and some slightly differing creatures, yet it's core narrative bares more than a small resemblance to the original. It's decision to kill off the main supporting characters from Aliens understandably made many fans very angry, and at the end of it the story doesn't really do anything that feels of much importance. But at the same time, this decision to be closer to the original manages to make it explore MUCH more interesting themes and ideas that originate from the masterpiece original rather than the good action film sequel. And so, as someone who is not a huge fan of the sequel, I found Alien 3 to be the more interesting and enjoyable movie. Just about.
The ending note of the 20th Century Fox theme sustaining is brilliantly skin-crawling in it's effectiveness, and instantly highlights how the cerebral and scarier atmosphere from the original is retained. The new setting helps the audience feel more unsettled and unsure about their surroundings like Ripley, and so the idea of a lone alien roaming the halls becomes scary again. Some characters are generic and it is strange to have one of the most well-developed supporting characters killed off an hour into the film. Yet there are certainly some characters that are memorable, such as Dillon being the spiritual leader of the group, and he turns into someone you grow to care about. There are nice moments of high tension and horror, and the plot has some twists and turns that you don't see coming along with a radical, risky ending (that IMO pays off because it's so different to the normal "happy ending").
And while it's far from perfect, I definitely found it to be more enjoyable then Aliens since it strays closer to the original in style. And I'm not going to say much more about this, because I know that I hold a VERY unpopular opinion about this film.