I really enjoyed this film, but it wasn't until I bought the CD that I realised how good the music was or how well it went together with the movie action.
There are some brilliant tracks and the sound quality/atmospherics also make it a very rewarding experience too. On the strength of this, I went to look for the original music for the Diva Dance section of the film. However, after listening to the "classical" version, I realised that I'd only enjoyed it becuase of Eric Serra's arrangement & performance on the 5th Element film & CD.
As ever, some of the "connecting" music makes sense when watching the film, but you may want to skip it whilst just litening. It doesn't detract from the overall enjoyment though.
And if you haven't seen the film, don't forget that too!