I was referred to Air-Zona by two friends who use them. I have absolutely no complaints with them.
They worked with my schedule to arrange a basic tune up for our AC unit. It was a non-urgent situation. The tech arrived on-time, a few minutes early actually. He made some recommendations on the inside of the home for optimizing our system and then up to the roof he went. Came down with tons of info about our unit. Did not make any outlandish recommendations for spending tons of money on it. The service fee was reasonable and he was done in about 30 minutes.
I will use them again and will refer others to them as well.