Unfortunately, I've never seen any version of the play except for the original movie, so I have little idea about the original play and the shows. But to me this movie is exactly like every other movie Matheau and Lemmon did since 1990, and it lacks the simplicity of the 1968 original which made them popular as a comedy/film duo. While the original was mainly performance and character driven, which is what made it so innovative, this one has little to do with the actual characters of Felix and Oscar and their bad chemistry together. It is more plot driven, which is what kills it. In fact, it could have been any two people with the exact same plot and nothing would change, whereas in the original the character's behaviour would have effected the plot a bit. Not only that, but there's no more satire and comments on marriage and divorce except the little bit at the end, which I felt was out of character for the play. You would think there would also be a comment on growing old and dying together, but there isn't because the plot gets in the way. Some may say that movies now have to be more plot driven and not as simplistic as they were 50 years ago, but I'd have to say they're wrong. A plot can still ruin a movie while one which is simply performance based can still make it today. Anyhow, the original is still much more popular.
Review of The Odd Couple II
