Ah, there go my hopes, dashed. Thanks for the input, I'll try it on a disk I don't need and see if it's unusable, thanks again.
I recommend at least trying ZFS out in a VM, I guarantee you'll be impressed by the versatility.
But know that to really use it, you want decent CPU speed, as much ECC ram as you can put in there, an SSD for cache (just one - doesn't have to match the raid size I don't think - it'l help a lot) and you still need to take into account all the normal raid cautious everyone ignores like rebuild times for 2TB sata2 drives -vs- failure rates, etc.... and if you want to use dedup without verify, that's your gamble.(smarter people than me say it's safe, but it just smells wrong)