AvP 2 is admittedly too bright at times and does not evoke atmosphere as well as the first game. However, having played it again recently, it still stands up as a solid horror/action game that paid respectable homage to the films in the series back when they numbered six, and featured a well executed interwoven narrative told from the perspectives of three relatable and vastly different characters.
A:CM was dead right out of the gate. It quickly descended into a dime a dozen generic shooter that may as well have been holding a sign saying "Hey. I was outsourced. " No matter how superior the engine was, it cannot outweigh that. And when Michael Biehn says he is not impressed even when you resurrect one of his favorite roles from the dead, you got problems.
AvP 2 does have its flaws, but it is still revered as a classic after over a decade by many in the community, myself included.