I wish I'd bought this a year ago. I'm doing progressive radon mitigation on my home. When I discovered the problem about 14 months ago, I first bought the Airthings 223, which gives accurate daily, weekly, and long term readings on its built in display. It was really useful, but I recently added this one, the Airthings 2911, and it has changed everything. I'm now able to track the ebb and flow across the hours of the day, week, month, year. Readings shown in hour intervals allow you to make sense of daily patterns and changes, for example, weather changes, family coming and going, thermostat settings, day/night, etc. Also exceptionally useful is having the data automatically laid out in graphs, to track against larger patterns like season change, cold fronts, and ongoing mitigation steps. Yes, you have to use the phone app or web interface, but both are easy (with fine-grained data on the web interface, much more so than on the 223). Also helpful, but secondary, are the other measurements. VOCs are nice to see (watching the profound effect of different uses of the gas stove, eg.), and the CO2 graphs are entertaining but not a real concern in my old, gas permeable home. Temp, pressure, etc., are mainly useful as a handy comparison as you're trying to make sense of radon changes. Purely in terms of expense, this has already saved me more than its cost by giving me the ability to pinpoint the interventions that count. Its accuracy matches fairly well the readings on the 223 unit, which in turn has matched other (charcoal sent to lab) tests I've run.Finally, if you like hard, detailed data, as I do, you can DL a CSV file with what appears to be raw readings EVERY FIVE MINUTES since the day you turned the sensor on! Takes a little auto-replace work to make the file cleanly readable in Excel, but, still, wow.