I really can't add much to Irishgit's excellent review here. I do think that the historians are taking a clearer look at Chamberlain. Most of the generations who trashed his reputation are gone.He was a realist and his defense preparations including building up the RAF and maintaining the navy saved Britain in the early years of the war.
His big mistake was extending the guarantee to Poland. Britain had as much chance helping Poland then as today Norway could spread its defensive wings over Nepal.