I decided to upgrade my slightly more than three years old 4-bay Synology DiskStation DS918+ to the 6-bay Synology DiskStation DS1621+.
Back in 2017, DS918+ was the flagship Synology 4-bay NAS and that was replaced with DS920+ in 2020. Also in 2020, the 5-bay DS1520+ got updated.
![Synology DiskStation Plus Series](https://live.staticflickr.com/65535/51008527223_a197ec73ac_c.jpg)