Very good, especially on differentiating the views of Gramsci and Bordiga even when in tactical agreement, as well as clarifying Gramsci's differences with the Comintern and his rejection of Trotsky.
A new edition of this is going to be released as part of the Historical Materialism book series, I believe. It's certainly well done, with a focus not only on Gramsci's life but on his intellectual formation and development. Once certainly gets a sense of what makes his particular 'theory of praxis', including it's Crocean origins and Gramsci's later transcendance of these themes.