I just buy a idrive wifi for local backup, It seems a very nice idea until I found that is not a incremental backup but a complete one. I have 3 machines with 500 or more gigas each one, It means that each backup takes at least 100 hours trough the wireless connection to finish.
For me is something incomprensible knowing that the online version is a incremental backup. It is is too much problem and time for such a simple task.