I go to the Summerlin Library for performances in the theatre. It holds about 300 people and is a perfect size for the community productions staged there. The first play I saw when I moved to Las Vegas was at the library theatre.
Acoustics are good and there is even a small pit for the band when a musical has live music.
I went tonight to see Signature Productions "Sound of Music." As usual, they did a fine job and took advantage of all the things that make this theatre a great house.