It is an interesting concept that when done right, only one household need to purchase such device and every device have protection. However, this doesn't stop malware not coming from the internet like an infected sub drive or etc. Since it is an interesting product, I preordered the box and maybe doing a brief writeup review when it comes out.
FYI, as I was writing this, Bitdefender sent me an email saying due to manufacturer issue, the box is delayed to Feb and extended the free subscription to 2 yrs.