As a 'horror', there are very few CGI/sudden effects that either kill the plausibility or become too graphically unpleasant. I liked the tone and pace of the story, and seeing it blind (unaware of reviews, story summaries or originals) I thought it was an intriguing idea. I felt the same way about US version of The Ring - quite solid, with interesting direction and style, but somehow just lacking something.
** POTENTIAL SPOILERS AHEAD - BE CAREFUL! **
The 'surprise' ending was signaled a long way off. I won't provide a direct spoiler, but about half-way through it became clear to me what was going on. It's a clever idea to disguise a psychological thriller as a ghost story but the punch is lost somehow in the way it's delivered (I read another review on here than indicates the original's ambiguity is significantly more rewarding). There are some annoyances throughout the film that become clearer once you know the secret (the father seems reticent while the omni-presence of the evil step-mother seems unlikely and irritating).
Overall, it's not a bad film - it's just annoying that it didn't make the extra distance to be potentially great.