In general (Spoilers)
I have just watched this and I wasn't impressed. Most of Christie's works - whilst entertaining in their time - have now become vehicles for the politically correct lobby who introduce male and female gay characters where none existed in the previous stories - and they even change characters and endings to suit their inflated egos. Big names and big sex seems to be their watchwords - and I can't be bothered to watch then anymore. I suppose they are trying to make her stories more plausible and up to date - I mean in Christie's world red ink can be mistaken for blood because nobody it seems has a sense of smell - twenty people with a motive for killing one can be found in the same room, ship, hotel etc. The same people will wait patiently in a room for an amateur detective with no power to detain to unveil the culprit - said sleuth is allowed to put evidence in his pocket - the last words of a dying person is why didn't they ask the maid. The list goes on and on - so these changes are brought in to disguise the inherent weakness and silliness of some of her plots.
I didn't find TWFTP engaging - the constant cough was pointless and annoying - he made a promise on the memory of his son and broke it which was implausible - his sex scene with his wife added nothing to the plot - we didn't need any of his back story. It was glaringly obvious that the villain was guilty and meeting up with them in the south of France beggars belief, as does his final solution.
The acting was OK - the story wasn't.