I've set up a couple of my clients with the "back up to friends" destination, and it works very well.
After reading about what you guys go through to back up, I realize that my backup needs are not the same as yours.
To begin with, while much of my data is precious to me, very little of it is "mission critical." If it all went away tomorrow, I would be unhappy, but my day to day life would not be hugely disrupted.
So, my backup system is maybe once a week or so back up to external hard drive(s), and maybe four times a year back up to a pair of 2-TB drives that I keep at my neighbor's house. Good enough for me, but YMMV.
tanstaafl.