Amazing and worth every penny. The guys showed up right on time. Scott and Brendan introduced themselves, explained the process and got right to work. I have an older home and it was evident that the ducts had never been cleaned before. Scott took "before", "during" and "after" pictures and there is no question that their equipment and skill are very effective. When Brendan had to leave early, they acted quickly to bring in a substitute from the office (sorry, didn't get your name) who cheerfully stepped in and enthusiastically got the job done. Following the guys around and watching them work, it was evident that they are extremely thorough and take their work seriously. I watched as they worked on a main duct, sending in numerous different tools to remove debris and then, after taking pictures, repeated the process, sometimes changing their approach and angle, never giving up until the duct was completely spotless. Really, really thorough - top marks from us all the way.