I've read all of Margaret Atwood's books, except Alias Grace. I read my sister's copy of Cat's Eye when if first came out and remember thinking: "hmmm, kind of a rehash of themes from earlier books," specifically Lady Oracle, in which menacing ravines also figure. It seemed a so-so, traditional effort after the more obviously audacious Handmaid's Tale.
Recently, however, after 9/11, i went through a phase where I couldn't read, couldn't find a book that could hold my attention, lead me into its world, make me care.
Came upon Cat's Eye in a thrift store. Revelation: how much stronger and sure-stepped it seems to me the second time. Atwood's expert handling of the slow power shift between Elaine and Cordelia affected me more deeply this time, perhaps because I've lived longer now and have seen strong friends falter and others, once dismissed as "quiet," emerge as the real, fierce talents.
Don't hesitate. Read it.