It also includes the little-known fact that Ted once tried to strangle Sylvia. Definitely best avoided.

The best book on them I've read so far isn't any of the Plath biographies, but Janet Malcolm's study of the biographies, The Silent Woman. She says some interesting things both about biographical bias and the subjects themselves, and treats them common-sensically as human beings with understandable issues, rather than taking up either the 'Plath-as-victim' or 'Plath-as-self-dramatizing-fantasist' lines. That one is worth reading.