While I don't mind some deviations from the book, there were too many changes in this one which were unnecessary and reduced the impact of the story.
As always, I enjoyed Geraldine McEwan as Miss Marple but in this movie, the annoying Raymond character actually detracted from many of the scenes Miss Marple was in. I think the writers thought this Raymond would be funny but he was irritating.
Changing the House and Gardens tour into a Mystery Bus Tour was another problem, since I found it hard to believe that these people selected by Mr. Rafiel would willingly remain when they are visiting places connected to their past which they wanted to keep hidden.
When I first read the "sisters" would become nuns, I was open-minded since it could have provided a way of tightening the story. Perhaps the Garden and House tour could stay at the convent and Miss Marple would meet the three sisters there.
But I didn't realize they would stray so far from the story by having Clotilde murder Verity in such a violent fashion and eliminating Clotilde murdering the second girl to pass off as Verity's body. That was Agatha Christie's clever twist, and while I don't mind changes from the source when it made sense, not using the most brilliant part of the story was a bad move and made this movie a weak shell of the book.