Uta no Prince Sama is a very very very typical reverse harem anime. In fact, its dating sim game origin can be seen clearly throughout the series. But, since reverse harem anime is such a rare breed, when you do spot one, it tends to be much higher quality than its counter part (harem animes, that is).
Being a music themed and reverse harem anime at the same time, you just can't help to remember the best (possibly the only till now) reverse harem music themed anime of all time, Kiniro no Corda: Primo Passo. In fact, as I mentioned in previous posts, the early part of the series literally felt like an reincarnation of Kiniro no Corda.
While the reverse harem may be its rise to fame, it also ultimately became one of its pitfalls: being a short season in the reverse harem realm, the focus of the story is almost entirely on the princes. The main heroin was only barely touched in terms of character development. You can argue the emphasis of the story is really on the harem princes, but as the central role that supposed to tie everything in, the presence of Nanami felt extremely weak. I think it has more to do with the length of the series--if it were a long series, they probably could have done a much better job than this.
Final scoreboard:
Drama: 82 (Reverse Harem Drama)
Comedy: 81 (For the little it had, it was pretty good)
Action: N/A
Art/Animation: 78 (Nanami's creepy eyes...)
Sound/Music: 90 (I do like their songs)
Character: 82 (All developed well except Nanami)
Plot: 80 (Typical reverse harem)
Ending: 80 (...)
Re-watch value: 20 (I wouldn't)
Overall: 81 - Reverse Harem Musical
Recommendation: On one hand, I think it's a decent reverse harem story that is done relatively well. On the other hand, it really offers nothing beyond that. So, it's really a tough call whether I would recommend this.