Bejamin is the technician. He arrived within the timeframe provided. He was personal, courteous and seems professional. I was a little concerned that the new flexible ducts installed in the remodeling last year may be damaged by the stirring device to dislodge the dust in the vent pipes. Benjamin assured me that the device will not hurt the pipes. After counting the number of ducts to be cleaned, he also inspected the blower and pointed out how dirty the blower was. He quoted me $478 for cleaning the blower, indicating that it is a lot more complicated and time consuming to clean a commercial grade blower, which is the type of blower installed in my house. Seeing how dirty the blower is, I realized that the blower was the source of dust build-up in the house, I agreed to cleaning the blower, even though the price seemed high without doing more research on what a fair price should be. To be fair, their quoted price at $299 for cleaning the vent is not bad. I just noticed that they are running a special at $199. But they didn't offer me the special to me when I first called. Perhaps for compensation, Benjamin did not charge me extra cost for additional vents above 15. He also sanitized all ducts and vents without extra charge. I was a little surprised how quickly he finished cleaning the air duct vents, probably less than 30 minutes for nearly 20 vents. I checked a few vents, they seemed cleaned but I didn't check the registers. He had a giant vacuum placed in the front yard, blowing dust from the duct system against my azalea shrub in the open air. He asked me to witness the process when he was doing so. I was curious why all the dust wasn't collected into a bag. He explain that the vacuum can operate in optimal efficiency when not attached to a bag. He said they always asked the customers if it is ok not to attach the bag to the vacuum. He might have but I don't recall. A few days later, I noticed that a few branches of the azalea shrub where the vacuum air was blowing against had dried out and died. After that, he spent the remaining 3 hours or so, cleaning the duct in the basement and the blower. I asked him to take a few pictures for me before and after he cleaned the blower. I also looked at the blower before he re-installed the blower back in place. It does look very clean. After air duct cleaning, I asked Benjamin to clean up all debris before leaving. He did remove the obvious ones. After he left, I still found debris or dust in a number of places. So I vacuumed the whole house again. Overall, I think Benjamin did a good job cleaning the air duct. It has been a week sine the cleaning. The dust doesn't seem to build up as fast as in the past. I would wait for another week or two to allow for better comparison. I think Benjamin could do a little better cleaning after the service is done, and be more cautious when blowing the vacuum air against shrubs. I would recommend No. 1 Cleaner again but be cautious of the issues I mentioned above.