I have been looking into them lately and reviews seems to be positive as far as battery performance and range. One negative thing to note is that they use a signal strength indicator relative to the location of nearest camera in range. So if theft is of concern its possible they could use the signal strength indicator to trace back to other cams in the mesh network, or at least its general area. Also, the pictures that are pushed from other cameras to the 'home' camera have a lower resolution than the pics stored on actual camera. Though people say they are still clear enough to make out what is needed.
Concept is great though and would be great to keep tabs on hard to reach 'sanctuary' areas and let you know when to move in. I will most likely purchase 3 or 4 this spring so far as further reviews stay positive.