I bought this book for my English lit AS level, and found it extremely useful. The notes are most useful as a supplement to notes learnt in school, as they are quite obscure but contain fascinating ideas and references. Although I was only studying poetry, the letters were also indispensable as a source of information on Owen's life, thoughts, and most of all the experiences which inspired his poetry.
Overall, a must-buy for A level English and also for anyone interested in WW1 poetry as it makes a very interesting read * 5 star Amazon review *