I have been a long time Netgear ReadyNAS owner, I started buying them not long after Netgear bought Infrant who originally made ReadyNAS.
One of their BEST features was being able to setup backup jobs that use SMB. This is a huge feature that very few NAS's have. Why?
You can back to/from a windows desktop/server file share. Because not everything has rsync
Implementation of an rsync "gui" for backups is inconsistent between brands and makes setting up and rsync job a huge pain in the butt
SMB is by far the fastest protocol on a ReadyNAS. My 628 model can sustain 9Gbps all day. Rsync on a ReadyNAS 628 barely gets 3Gbps, scp gets only 1.8Gbps
While my Netgear 628 is old, unsupported and running an ancient kernal. I intend to use it until it dies with no spare parts able to be found for it. Readynas has been incredibly reliable for me, I've never had the hardware die on me. Just hard drives.
I believe many other people would enjoy having backup jobs able to run via SMB as well.