He's white; He's in his 40s; He lives in a small town; He listens to classical music; He drives a fairly simple car; He learns all his medical knowledge from library books; His family die from the disease; The dog is a stray; The woman is a vampire; His neighbour and workmate plagues him throughout; The ending isn't sugar-coated.

He's black, in his 30s; He's a Doctor in the army; He lives in New York; He drives a Ford GT & a huge 4WD; He listens to Bob Marley; His family die in a helicopter crash; The dog is his daughters; There's a little kid and a non-vampire woman; There is a typical modern holywood everything must end nicely ending to it.

The "Dark Seeker" leading the attack on the house was the same one in charge on the pier at night, the same one who set the trap with the dummy... and the same one who risked popping his head out in the sunlight when Neville took the female "Dark Seeker". I took it that it was after Neville as Neville took his mate.

Movie: The Dark Seekers invade his house. He dies. Non-vamp girl & kid escape & take the cure to the "Survivors' Colony".

Book: The girl is one of the infected others, the group that have the infection, but aren't full-on undead vampires. The half-infected, or whatever you want to call them, capture Neville, & plan to execute him, as to them he is a monster, & a remnant of the now dead human civilisation. The girl gives Neville some pills so he can take his own life.

I think it would have confused & complicated things if there had also been half-infected people who weren't full-on "Dark Seekers", plus in the movie Neville didn't go out hunting the vampires / "Dark Seekers", so wouldn't have done anything to anger the half-infected & cause them to hate him & want to execute him.

The ending...OK, bit too happy, but at least Neville still died.

Well its quite possible the story aimed to mislead us on their mental abilities, but Neville made it clear they lost sociability, so even if there was an exceptionally intelligent one the others would have had no reason to obey.

I think that's where the movie got let down, it was a great movie but could have been much better.
What I got from the Dark Seeker leader was that Neville captured his mate, and being leader managed to get the rest to attack, so Neville was being presumptious in believing they had no social structure, or the script writers ballsed up.
The thing about the trap that was laid for Neville was, how did they get hold of the equipment needed to fire a spike into the ground and set up the cable etc without a high level of intelligence.
Likewise, if the virus turned animals into savage beasts hell bent on just attacking anything in site, how come the infected dogs were tame with the Dark Seekers?