Uh, they're pretty much one and the same, considering they're in the same universe and all, y'know? But I'm much more interested in Prometheus 2. I want to see more of the engineers, and I want to see the aliens through the eyes of Ridley Scott again. I also want them to be in a deep, ambitious movie. I'm done watching them hobble after people down corridors. I want a bigger universe, thematically and scope-wise.
Plus, look at Prometheus' box office gross. Its blu-ray even defeated Avatar! An Alien 5 would never be able to accomplish that. Well, an Alien 5 post-AvP/AvP2/Prometheus, anyway. Back then when Ridley and James were working on it, it would've had blockbuster potential.
I still don't understand that. You could've advertised "From the director of Alien and Gladiator" AND "From the director Aliens and Titanic". Amazing.