It was late. I needed a cab to Sky Harbor for an early flight the next morning. I called other cab companies and got answering machines. "Leave a message. We'll call you back." I didn't trust that system. Camelback had an actual human being answer the phone and schedule the appointment. I felt relief. And I was even more grateful when the cab driver showed up early. It was a reasonable price and everything went smoothly. I'll be calling them again.