The night is dark as fuck, literally can't see anything without your flashlight, but all enemies (except biters?) react to your flashlight now, volatiles wandering around will see it so you gotta put it away quick.
Started a chase during the first mission trailing something, had to turn off my light to try and hide, ended up falling to my death because I couldn't see anything.
As for specs I have a 7 7700x CPU (they actually recommend this) and an RTX 4070 (above recommended) and it's running great so far.