Loop, maybe south...late night?

My parents are going to Wicked tonight and we're going to grab a bite afterwards. I've been to Cuatro...so that may be a possibility? Any opinions on Solo 1530? Also, do you know how late Zocalo serves? Anything else in the south loopish area?

I'm pretty sure Eleven City Diner is open late.

Go figure, the website doesn't have any hours that I can find.

http://www.elevencitydiner.com/home.html