I have used Shamrock for about a year now after signing a yearly contract for semi-annual 'tune-ups'. I am very happy with them and their service techs! Rocky came out today for a service call and was on time, did an excellent job, and explained his findings in a clear and consise manner. I've had the experience with MANY other service companies who are late or they call you at the appointment time to tell you they are going to be another hour, or two . . . I appreciate good customer service and Shamrock delivers!