I just used them for an unusual issue at my workplace involving an a/c unit attached to a pumpstation. I called them around 4pm on a Monday, and the lady who took my call was helpful and knew their schedule for the week has really busy but she wanted him to check it out in case they needed to order parts.
After a couple more phone calls letting me know the status, Kevin showed up around 7pm M&K is a mom and pop operation and Kevin is the son. He did a nice job diagnosing the issue with this strange unit (he'd never seen one before). Just a basic cleaning, and there was a small refrigerant leak.
They came out on a Sunday afternoon to make the repairs. Kevin couldn't find the leak, but inserted a coating inside that would seal up any small leaks. They cleaned up a machine that probably had never been serviced and was filthy. Kevin even notified me of an alarm on my pumpstation that allowed me to come in and get working for that nights irrigation.
Great job, great service...no complaints.