What do I ask property management references?

[Elijah White]

My wife and I are renting out our house in Kansas and moving into a new house in Texas. We have decided to use a property management company rather than trying to self-manage. I have found a company that has great online reviews, fair prices, and seems to have their act together. They have provided me with a couple of email addresses of current customers to contact for references. What are the most important things I should be asking these references in regards to their experience with this property management company?