Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
I have 5 NAS's from different manufacturers such as Qnap, Synology and Thecus. Thecus is not as good as Synology or Qnap, but they are ok. Their OS is not as full featured and I have had more issues with the Thecus then the other brands. I would spend a little more for a Synology if I were you.
with 4 disks no need for hot swap spare. I don't think you can RAID 6 3 disks with a hot spare. You can afford 2 failures on raid 6 with 4 disks. I'd say RAID 5 with that few disks as well and afford one failure with no spare. Just have an extra drive around and pop it in.
the N5550 is a 5 disk model, that was why I asked about spare.
After looking at it and hearing opinions I decided its 2 year old model and its not bad but not what I want.