Are there any other NASes out there that a) support ZFS/BTRFS, b) support different-sized drives in a single pool, and c) allow arbitrary in-place drive upgrade

Are there any other NASes out there that a) support ZFS/BTRFS, b) support different-sized drives in a single pool, and c) allow arbitrary in-place drive upgrades? Last I checked, I believe I didn't find anything that satisfied all three. So DSM sits in a sweet spot, I think. Plus, plastic or not, Synology hardware just looks great.