I'm a high school Spanish teacher, not a specialist. I saved a review of this translation in the New Yorker, Sept 8, 2003. I don't have the name of the reviewer. One paragraph:
Fortunately, Neruda's best work has attracted his most gifted translators. Without them, his best might appear to be a good deal less. Examples are W.S. Merwin's translation of "Twenty Love Poems and a Song of Despair," Jack Schmitt's translation of "Canto General" and "Art of Birds," Margaret Sayers Peden's translation of the three books of "Elemental Odes," and Alaistair Reid's masterly translations of "Extravagaria" and "Isla Negra." These works alone would easily be enough to provide many hours of happy reading.