Product review (3 stars): Too pricey for a collection
First, I will state my single device was offered in exchange for evaluation via the Vine program. I presently use a room type hygrometer for my two guitar rooms  (I am in the midst of downsizing my personal collection.)  I have compared the results by putting the room device in a case at the same time and the results are comparable.  However, they do not differ enough for me to take alternate humidification steps if the D'Addario was more accurate as my current method appears to be working.  That said, I am a technology junkie and it would be interesting to keep track of each guitar individually due to variations in cases and tone woods.

However, after checking the price, it seems to me unless you were limiting usage to 3 or 4 guitars at most, the cost will add up.  I am also troubled that the majority of negative reviews also come from people managing multiple guitars, which makes such an investment even more dubious.

For now, I will continue to rely on individual humidification devices and environmental controls of my storage rooms.