I read the book prior to the release of this, and I have to say it isn't a favourite of mine, nor was the awful Marple adaptation some years ago.
Laurie has managed to make the story into a really enjoyable, watchable whodunnit. The acting was great, I thought most of the characters came to life.
The best element, the visuals, it looks incredible, great fashions and cars, plus some sublime location work, surely one of the most picturesque places in The UK.
Nowadays, it's advisable to approach Agatha Christie adaptations with a degree of caution, you have no idea whether you'll find Poirot taming lions, or Jane Marple making ice sculptures, but credit where it's due, it's a faithful adaptation, without any massive changes.
If I'm honest, I thought it dipped a little in the middle, but overall it was very watchable.
Let's hope we get more quality adaptations soon, this was very good, 8/10.