That's a really cool idea and matches my use case well. I just copy pasted it to another person in this thread who was asking about the ZFS setup.

Your use case perfectly matches mine in that I wouldn't mind much about a few hours of data loss.

I guess the one issue is that it would require more disks, which at the current prices is not cheap. I was suprised how expensive it was when I bought them 6 months ago and was even more suprised when I looked recently and the same drives are even more now.