Continuing with my PS3 impressions.
Just because the game doesn't stand up to the huge hype doesn't mean it is bad.
It does entertain as long as you don't expect to be wowed.
I'm on chapter 2 now (I play as slowly as I can to enjoy the atmosphere) and yes, there are gunfights with humans that are as generic as they come and will probably bore most of you.
I would like to point out that on the PS3 so far, I haven't experienced framedrops, glitches or notable aliasing.
I play on the "soldier" difficulty and although the game is not hard, there are some difficulty spikes here and there. For example, some Aliens may give you time to finish them but sometimes they will circle around you and attack fast, killing you with 2-3 blows.
I like the bro-talk in this game. It is consistent with how the movie portrayed the marines.