I enjoyed this very much, with a couple of reservations. Firstly, I should say that I failed to identify the murderer which is a surprise because I thought I had Christie's methodology down flat. I was blinded by my own cynicism - or possibly I didn't exercise enough cynicism, it's sometimes hard to tell. This is supposed to be one of Christie's greats, and I suppose my experience reflects that. 
 However, this does feature a more than usual of the "crooked = Greek" type of characterisation that Christie is sometimes troubled with.