I recently got one.
Initially I wanted to go for IQAir by joining the group purchase organised by one of the mothers but was very disappointed by the sales technicians who came to our home to do the air quality test. They simply had a device which showed the number of air particles in your home and then showed how IQAir could remove close to all of the air particles. But you know, not all air particles are bad...could be just dust. We wanted to know more about what the composition of air particles were, eg pollutants, CO2 etc. but they were not very helpful.
In the end, we contacted another company recommended by a friend and he WAS GOOD. He came with a few devices, explained what the compostion of the air in our apartment was, and then simply said we do not need IQAir where we stay (although his shop does sell IQAir as well!). He recommended that we buy AmairCare just to remove pollutants from the traffic and it cost us 1/3 the price of IQAir.
We use it for our baby son's bedroom at night when he sleeps and have been very pleased with it .