Product review (5 stars): Great way to measure temps and humidity in a single attractive unit.
I have three of these monitoring temperature and humidity in my vacation home, and so far, they are doing a fine job. My vacation home is in coastal North Carolina where high humidity levels can lead to all sorts of mold and mildew problems and the humidity information I get from these units lets me anticipate and react to humidity levels automatically to keep humidity under control .

In my case, I have these sensors connected to a Homeseer unit (I have an older set connected to a Vera 3, and it works equally well). Pairing was easy, and so far everything has pretty much worked as advertised. You can run the sensor in a way that the sensor sends alerts only when certain thresholds are crossed (say, humidity exceeds 65% or drops below 45%)...in this case, there's not constant polling between the controller and the sensor, letting the batteries last much longer. You can also poll the device to query instantaneous conditions if you want to know the current conditions precisely. With lithium batteries, I'm expecting perhaps two years.

I also like that the display is visible in the room where they are used. I don't need to go look at it from my home automation unit - at a glance, I can tell whether humidity is what I expect or not.

I'm not completely sure how accurate these units are. I have a few other sensors that can report humidity, as well as an old fashioned hygrometer, and even when all the sensors are in a room just a few feet apart, they all report different numbers - often as much as 5% difference. Still, I just really care about the trend and whether humidity is increasing or decreasing...I use these conditions to control my dehumidifiers and HVAC system, and for that, it works well.

Only other issue I have with these units is that I wish there were a way to connect them to a power source other than the internal batteries. Some other brands have a micro-USB port that can be used to power the device without batteries - I'd definitely like to see something like this. Also, the programming process is a bit confusing with too many buttons to push...I'd rather have a "wake up" button on the device, and then use Z-wave commands to program the unit the way I want. Minor issues overall though.

On my Homeseer, I have software that uses current and forecast weather conditions to switch between ventilation only, dehumidification and air conditioning, and I'm able to automatically keep humidity levels where I want them without running dehumidification 24x7 - and saving me at least $50/month in electricity. Since I'm not always there, I need high reliability and confidence that the system will work properly unattended, and so far the Everspring units have more than met expectations.

Definitely recommended.