It's unfortunate, yet very fun that this is the first comment I have ever written on a Movie on IMDb. The earlier movies I wanted to comment already had everything said by others. But this film I have to praise for many things, yet hate it for others. You will probably know what I mean when you see it - but I can say so much without spoiling anything, that the only saver for this film (reason for not totally hating it) is that it is "based on a true story". Sure, it is probably as "based on a true story" as Texas chainsaw Massacre, but still. This is the most violent movie I have ever seen, and it is so well-made, that I got the worst chills down my spine I ever gotten watching a movie. And I'm a fan of ultra-violence movies, so far the films which I can compare to this is The Hills have Eyes and Hostel. Even though I found those two movies pretty violent, Carver just kicks those two down pretty far on the list of hardly-watchable violence.
I have to say that it is the best "special effects" I have ever seen, when it comes to violence. I base the following on absolutely solely the movie itself, but I think the CG in this movie is absolutely minimal. It all looks so real, it all has to be a masterpiece in latex/mask effects. And I might add, that I really despise 3D implements in horror movies. And I say that even though that myself is an 3D animator, which maybe explains a little better my opinion of the quality of this film.
I'm sorry for miss-spelling and such, I don't very often write in English. Enjoy the film!