I thought it was OK. But, yes, I though "huh, this looks and feels a lot like Alien" all the way through the show. At the end I had a "well, duh" reaction.
I did not know going in that it was a prequel. If I had I would have probably enjoyed it more, since it was answering a lot of questions about the Alien universe {and raised a lot more}. It would have also made the plot parallels more palatable, being almost inevitable coming from the same universe. As it was, I was more likely to think they were being copycats, but at least not cheep copycats.
Of course, if I'd known, I probably would not have watched it at all. The Aliens movies are pretty low on my radar for must-watch movies.