I will start with the fact that waiting 20 minutes for any sort of coffee is not worth it when you are spoiled with the Las Vegas environment.
It is worth it if you prefer getting an ice water with any of your Starbucks orders though. Be sure to order water when you are here. Dehydration, exhaustion, and soreness occurs when you are in an outdoor mall!
Expect long waits, possible mistakes on custom orders, and no tables to sit at.