Definitely would recommend. I just bought a house in the Hyde Park area. It is an older house, but I could tell just by looking at the vents that they had not been cleaned in years. I was having issues with my breathing, so I decided to have them cleaned. You have to schedule pretty far out in advance, but it is because they are very busy. They gave me a time window of 8-11 and showed up right in the middle of that window. I opted for the full cleaning and sanitizing because my vents were that bad. The two guys that cleaned my vents did a great job. He recorded the vents before and after and I could not believe the results. He also showed me what had been caught by my filter and sucked up by the vacuum. Would highly recommend to anyone purchasing a home to have this done.
After they left, I was feeling uneasy about the quality of work that was performed. I used a camera to get some video of the vents that they cleaned. They looked pretty good, but then I started to remember how they were cleaning them. They only used their large, commercial vacuum on one vent. They also did NOT clean 2 air returns under Negative Pressure like the Groupon said they would. I did a little research and found that they should have cut open an access point in duct work in the basement and sealed up the vents with plastic to create that negative pressure.
They arrived within the time range I was given, and they even called about 20-30 minutes before arrival, so that was appreciated. They arrived and started bringing some equipment - A shop vac (yea, like you can buy at any hardware store), a handheld vacuum cleaner, and large vacuum that came in on wheels. After showing them the locations of all of the vents in the home and cold air returns, the technician (Simon) started going over a few things with me about their plan for cleaning and showing me the dust & dog hair build up in one of the vents. After showing me that, he started to try to up-sell me on additional services. That additional service was to insert a 'brush' that would agitate the dust/pet hair and allow for the vacuum to get everything out of the vents.
Compared to using a duster or changing out air filters, professional duct cleaning means going through all the many elements of the HVAC system. This includes, but is not limited to, the supply and return air ducts, grilles, diffusers, exchangers, heating & cooling coils, drip pans, fans and the air handling unit. Keeping these maintained means avoid problems like pollen, mold or overt dust buildup. This is definitely a problem you want to avoid.