I feel compelled to write my review to balance the bad ones! First things first - IF you don't know the musical OR T.S.Eliot's poems AND you don't like whimsy - you will probably flounder watching this movie.
The plot is simple; different cats auditioning to be the one chosen to be reborn (remember cats have 9 lives). Each cat has his/her unique story. They are Jellicle cats - and proud of it! (refer back to knowing T.S.Eliot's poems)
The movie does a very nice job of giving a central role to Victoria, who is in the movie but not as a principle character. I enjoyed her song as a response to Grizabella's. It also gives Macavity a more tangible role as the "bad guy" whereas the musical just speaks about his life of crime.
I was pleasantly surprised that some songs/parts of songs were pulled from the London set. I had to go back and re-listen to my soundtracks as I am so accustomed to the Broadway set. I have seen the musical several times (and would do it again if it came close to home!!). The movie actually filled in some "blanks" that I never even knew I had from the musical! Scenes that made me go, "Oh, yes! That makes sense!".
So please - do yourself a favor. IF you don't know the musical or don't know T.S.Eliot's poems - don't go. A for heaven's sake - don't write a trashy review saying it would have been better watched under the influence!! To each their own in this world, I say.