I think that unless a reviewer gets their facts completely wrong, the author should shut up. When you publish a book -- when you make art -- people are free to say what they want about it. You can't tell people they liked a book they didn't like, and there is, in the end, no arguing with personal taste. Different people like different things. Best to move on and make good art as best you can, instead of arguing.
Neil Gaiman: http://journal.neilgaiman.com/2004/09/de-gustibus-and-how-to-reply-to-bad.asp