Background: I picked the wrong type duct cleaing service. Subsequently I have learned tthere are two main types of duct cleaning services... and I have found they are not equal in their cleaning ability. The first type uses a truck mounted large industrial-sized vacuum that is attached to the heating system with large flexible fabric 'hoses" and sucks large volumes of air through the ducts simultaneously as a pneumatic "beater / flailing wand" is manually threaded by the operator though the ducts to loosen dust and debris contained within the ducts. The wand is flexible and snakes around bends and right angle corners in the ducts. The loosened dirt is then rapidly drawn out of the duct and into the vacuum bag filters in the truck. All the vacuum machinery remains outdoors in the street or your driveway. I've heard this referred to as a "negative pressure" type duct cleaning system. This system requires somewhat more time to set up and a sizeable investment in equipment. This is the type cleaning system I assumed would be used... but wasn't. It was my fault that I was not aware that other types of duct cleaning systems existed... and therefore did not verify what type system that would be used on my job. It turns out the second type duct cleaning system is one that uses a rotating brush mounted on the end of long hose attached to a man-portable vacuum cart that is wheeled into and through your home (about the size of a patio barbeque). The grills on your home's heating outlets and return air inlets are removed and the hose with rotating brush on the end is inserted into each outlet and inlet by the operator. The hose is then pushed as far down each duct as the hose length will allow (usually 30' to 35' for the 40' hoses commonly used). The hose typically does not go around right angle bends. The vacuum hose then sucks up dust and debris loosened by the rotating brush... but only for duct lengths not exceeding the hose access length. I've heard this referred to as a "roto-brush" type duct cleaning system. This system requires much less time to set up...a much much smaller investment in equipment and can easily be transported in the back of a family SUV. This is the type of duct cleaning system that was used on my job... but I wasn't expecting. Again, this was my problem that I did not verify the type of system to be used. Aegis used a roto-brush system which didn't have a vacuum hose length adequate to access the full length of my home's ducts as it turns out. I was not told of this situation... and the operators themselves may not have been aware of it... although they should have been. I believe they said their hose was 40' long. Unknown to me... but discovered a week or so later... large lengths (at least 6' to 8') of my ducts were not cleaned at all due to inadeqate hose length and/or inability to negotiate around duct bends. Also I found that remaining dust and debris was still visable through the open outlet & inlet ducts immediately upon "completion" of the cleaning job. I called this to the attention of the operator (while he was still on site)... who then re-cleaned these duct spaces. This made me wonder what else hadn't been cleaned adequately. I later found out. Although the two operators turning up to do the job were polite and accommodating... they did not impress me as being very professional. Hip-hop shorts, raggedy T-shirts and flip-flops did not strike me as appropriate dress for a professional service coming into a person's home. They arrived in an unmarked personal SUV with out-of-state plates (Calif. I think) with the roto-brush machine loaded in the back. After being on the job site for a few minutes...one of the two operators said he had a headache and needed to go to a drug store to get some aspirin. He didn't return until the job was nearly completed by the second operator in a little over an hour or so. Their job price was about half of what I have paid in the past for professional duct cleaning by a contractor using a negative pressure duct cleaning system. I mistakenly assumed I would be getting the same type service... but at half the price. My error. In the future I will only engage contractors using the negative pressure type system and specializing in duct cleaning. To me it's worth the added price given the better results I've experience with negative pressure vacuum systems. For those homeowners having duct work compatible with a roto-brush cleaning system (shorter staight duct runs, no sharp duct bends, visibility allowing verification the cleaning has been done adequately, etc.)... I would check out several contractors before selecting one... to find one that is conscientious, professional and effective. I did not follow-up with the contractor to complain or request a re-cleaning. I figured it would not be worth the effort given the nature of their roto-brush system and the hose lengths of their vacuum. I simply manually vacuumed out the uncleaned sections of duct work myself as best I could... when I later had the furnace taken apart for unrelated repairs. But, all things considered... I personally will not use Aegis again.