Very fun!
Kenneth Branagh's Hercule Poirot is as delightful as the sugary confections he devours.
I just love these movies, like Ten Little Indians and House on Haunted Hill, where everyone's trapped and paranoid ;-)
IMDB has it sitting at 6.7, and it's a full point higher than that, though yes, sure, it does—ahem—stall a bit in the middle.
Alas, it turns out alright, and is fun en route nonetheless, if for no other reason than to see such a huge cast assembled and suspect!