These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Base Breaker: Junior in the remake. Was he a compassionate and troubled kid who was the only member of Krug's "family" to have a conscience, or a derelict and wimpy Jerk Ass who set the whole ordeal in motion due to his defiance? The latter is understandable, considering he was the one who brought the girls back to the room, even though Krug specifically told him NOT to do so and even then had a rather weak rationalization of "I didn't know you'd be back", and during the moments of strong brutalization of the girls and when he was able to shoot his father, but didn't cause him to be this. Fridge Brilliance could say that he almost never stood up for anything or even tried to run away was because of being abused all his life by his absolutely wretched father, still people argue he should have known better (but then again, so should have the girls), plus the fact that Dr. and Mrs. Collingworth are so forgiving of him and that he is lead away to safety with Mari and her family also pissed off quite a few fans.
Complete Monster: Krug is the leader of a group of murderous rapists. After he and his gang escape prison for their previous crimes, they kidnap, rape, torture, and kill two teenage girls. The parents of one of the girls find out when the criminals incidentally stop at their house, leading to a bloodbath between Krug's group and the parents. Aside from leading a group of horrible rapist scum, Krug also brainwashed his own son and kept him hooked on drugs as a kid as a means to control him. Near the end of the film, he convinces said son to kill himself. So yeah, you definitely root for the vengeful dad to take Krug down with the chainsaw.
Moral Event Horizon: If you had not lost faith in Krug when he rapes and kills Mari, then you will when he convinces his son to kill himself. As the latter doesn't happen in the remake, you'll lose any interest in seeing him live when he brags about raping Mari and how much he enjoyed it to her father while beating him up.
Narm: The original has a fair amount. Hey, it's a low-budget '70s horror flick.
The bumbling comic-relief cops manage to wipe out most of the film's tension every time they step into the frame.