How reliable is the network - will you be able to cope with Sandy style blackout?
Will there be a software component in which I designate a hard drive on my (always on) pc and skip the external device entirely?
How many times the data will be backuped?If only twice than if my home device get stolen/eaten by a rabbit/simply breaks then it is needed only one hardware failure somewhere else in the system to have stuff lost forever.
Regarding durability, the Kickstarter page mentions:
Q: Is my data safe?
A: Yes! Super safe. Here’s why: when you put files in
Space Monkey, you not only have a copy of everything on
your Space Monkey device, but each file is chopped up into
tiny pieces, encrypted, then stored to dozens of locations
outside of your home, in such a way that even if half of
those locations were destroyed, all your files would still
be safe.
_Normal Accidents_ by Charles Perrow
Please, please read this book RE: complex, tightly coupled systems.