I recently started watching this show a few months ago (it is shown on the televisions at the gym where I workout). When it first came out I thought it would be more along the lines of "Bewitched" only with more of the single girl on her own slant of "Mary Tyler Moore". However, as I started looking at it, it really was more like another creation by the late Aaron Spelling, "Charlie's Angels". The show pretty much is one of your standard issue action series with a supernatural twist. However, the thing that saves it is the relationship between the three sisters. Also, to me the show seemed to pick up steam once Shannon Doherty quit and was replaced by Rose McGowan. That seemed to put more of a humorous element into the show that it seemed to lack due to her character Paige's lack of experience at being a witch. This definitely is one interesting show.
