They have a very extensive selection of the popular singers -- Amuro Namie, Crystal Kay, Utada Hikaru, Hamasaki Ayumi. However, they did not have the Double song I wanted to sing. Otherwise, they are pretty solid, with the choice to sing in Tagalog or English, as well as other languages.
The milk fruit drink I ordered wasn't very impressive, however. I didn't drink it until I was finished singing the song, and by then, the gel had separated into a thick layer floating above the watery milk. Fortunately, my friend ordered regular fruit juice, and hers was good.
Sound proofing is good in general, although you can really hear the people in the next room if they started belting it out!