The backgrounds, colouring & imagery are lovely and the dances impressive and sparkling.
But I find it necessary to emphasize the mixing/editing as others have done. Some of the numbers contain video from 3 different shows. Therefore (as mentioned) sometimes the colour of the dancers' clothes very noticably changes between red and green whenever the camera view changes, for instance. Of course the lead dancers also often magically change within these numbers.
The music is excellent and runs smoothly. However this means that the music comes only from one show at a time. While the editors have done a very good job, occasionally you notice that the video from one or two of the other shows isn't quite in sync with the music. If the show didn't contain tap dancing, I might not have noticed - unfortunate.
I think Riverdance is excellent and there were several numbers I hadn't seen earlier, but I'd rather have the Live from New York version, which I expect to give 5 stars. Make sure you get the version you want.