Build quality and features are better than any other fire alarm I have tested. Unfortunately, a software bug (?) Makes it unusable.
After a firmware update, the battery life is between one and two months, if you use the recommended (really expensive) batteries from Energizer, and even shorter (days) if you use regular alkaline batteries. The problems have been widespread and persisted for over half a year, but Google seems to be completely out of hand, and can't solve the problem.
The fact that such a bad firmware has gone through all the tests and QA processes of a unit whose task is to save lives does not immediately give any confidence.
I have currently returned to a regular fire alarm for SEK 99 instead.