Beware: other reviewers have been spot on in their complaints about the wait times at this location. Over the past few years we've been here (it's the closest AT&T company store to our home in Summerlin), the overwhelming majority of times we've waited upwards of 20 minutes for help, even if they're generally friendly and helpful when they finally get to you.
For simple issues (i.e. picking up an online order, purchasing a case, asking a quick question, etc.) as well as advanced ones you have to queue up in the same line until a rep can assist you. Since many of them are often in the midst of setting people up with plans, or sometimes take breaks all at once leaving almost nobody available, it can take forever.
We stopped by the Sahara location recently and they were both a lot faster at getting to us and more efficient at handling our transaction compared to here. If possible, take the alternative.