I just installed an RS3621xs+ to replace a DS2415+ that I've been using for over 5 years and it works well but it's very slow, and buy an RS3621xs+, buy Seagate IronWolf Pro 16TB NAS Hard Drive and they don't work with this NAS when you look at the compatibility list only 11 hard drives are compatible with that NAS and only 2 over 12 tb , both Synology one of 12 and one of 16 and the 16 is not available someone knows something about this