I thought the storyline was great and I enjoyed all of the "jumpy" scenes but I really wanted to hear more of the backstory about (nonspoiler) the woman in black and her family.
I thought Daniel Radcliffe did a great job with his character. The other characters in the movie were really just bit parts, so nobody really commanded any attention - which may be another downside.
As for the scare factor, I enjoyed the little ones but it was more creepy than scary. It didn't make me leave the theater talking about how scary the movie was but of course it was more of that "supernatural" scary which could be part of it.
Overall, I wouldn't waste my money. Go watch the Grey!