The best about this OVA is the music which is really nice to listen too - nothing to memorable but it's relaxing and simply nice. The best songs are naturally the concert songs from the endings of each episode - especially ep 1 and 4! They are just catchy and you want to sing-along. The character design and animation is beautiful and charming. It's funny to see how it changes from ep to ep though.
The idol parts like modelling and singing were nice to look at - also the flights. Storywise it's nothing much to tell home about - it's a nice story about some sisters and their rivals and friends which tries to get some action into it. The mix of piloting and singing idols is somewhat strange but not bad.
If you like beautiful character designs and nice music without much story to back it up you might enjoy it!