Just my two cents. It is not a backup. It fails on a few tests which are simple. No write protect switch and and a virus/trojan/spyware/other can easily infect/destroy the information on this drive.

It is, in fact just a second copy and not a backup. A backup would be readonly so when you go to restore, if a virus/other was at play then it would survive.

Nice idea, but it is flawed from the outset.