And that's the thing. I used SmartOS for a while and while there's nothing wrong with a ZFS root, per se, you're still at the mercy of boot loaders and whatever

And that's the thing. I used SmartOS for a while and while there's nothing wrong with a ZFS root, per se, you're still at the mercy of boot loaders and whatever Amazon will or will not let you do. So I've taken to having ext4 or whatever as the boot drive and a zpool for anything I care about :)