I think that if the "Brothers Strause" (whatever they like to call themselves) had actually learned from the mistakes of Alien3, Alien Rez and AvP, and if they made more of an effort to make it "realistic" (i know the main characters are aliens), it would'vs been a much better movie. AvP is also full of mistakes, but far less of them, so thats why I think AvP is better.
P.S Requiem was a cool word... once.