Two stumbling blocks seem to stand before biographers: venereal diseases and blaming of the partner. Kildea avoided none of them. In respect to the former, he made Britten rejoin the glorious company of Schubert, Wolf, a.o. In respect to the latter, he made Pears rejoin the no less famous company of the biographers' "bêtes noires" - Konstanze Mozart and Sophie von Kühn (Novalis's fiancée) come to mind. Kildea needed Pears's "bad behaviour" (based on a hearsay theory of one person who disliked him) to support his speculation about the venereal disease and further "bad influence" on Britten. Now Britten's supposed disease has been rebutted by several of his doctors (Kildea's misfortune is that they are still alive) and the misrepresentation of Pears is contradicted by first hand sources like the six volumes of "Letters from a Life" and witnesses of people who knew him well (his and Britten's biographer Christopher Headington among others).
The main point about these errors and inaccuracies is that they cast doubt on Kildea's research or seriousness and therefore I can't really trust him as a biographer. Too bad, because the book is corrective of some of Carpenter's major flaws but it contains also, in addition to the main speculations, some misleading half-truths (e.g. some half-told stories which when complete - as they can be found in other books - share a different light on the narrated events). Kildea's avowal of disliking Britten as a person gives him some apparent credit, but this too is a fashion among biographers: lest one be accused of hagiography, better say the music is good and the man not so good. So few is said for example about Britten's kindness (called "hatred of confrontation") for which there exists nevertheless touching evidence (Fischer-Dieskau for example, in "Echoes of a Lifetime", and others).
For me the best part of the book was the description of the cultural background in Britten's time. On Britten himself and his music, I appreciated some insights (e.g. the profile of Britten's ideal musician, the international quality of Britten's music, the notion of "innocence betrayed rather than destroyed") but couldn't adhere to some others (his supposed narrow understanding of women for example). I was disappointed by the commentaries on the early operas (endless discussions of librettos, e.g.: Lucretia: three pages about the libretto, no word about the music; Albert Herring: four pages about the libretto, two lines about the music! - quite curiously, because in other places Kildea himself finds criticism of librettos pointless) but I appreciated some other musical analyses (of Canticle V, The Prince of the Pagodas and the 3rd quartet to quote only a few). These could have made some good essays, but as a biography the book was for me rather disappointing, especially the second half of it.