Mark, and I believe Lisa, handled our cleaning last week. Since then our homes air quality has been noticeably improved.
Our home is quite old (built approximately 1915 apparently) and has been neglected by the previous owners for about 10-15 years, so basically everything needs attention. They were pet owners too, which just adds to our cleaning.
We had to go with the Silver Package due to our budget but we'll definitely be in touch in a couple years for the full package. The work they did was very thorough on our vents and when I explained a problem area within our air return (see photos) they made sure to concentrate their efforts to clear it of all debris. It took a couple attempts at clearing the vent because of the wires that had accumulated the pet hair and everything else but they were able to get it.