I've got mixed feelings.
I've only just read the book so it's all pretty fresh in my mind.
There were a few cases missing (the missing husband, the Patel girl, the doctor who was good and bad and others I can't recall off the top of my head, the secretary isn't really as described, there is no camp crimper and she had another 'Gentleman friend' who also asked her to marry him (the Doctor I think)
But it did very much have the essence of the books and was lovely TV. Can I also say that I thought the gangster chap was very lush in his specs