Seagate BlackArmor 420 is a decent NAS server. However, not having the capability to dynamically change the current RAID setup's capacity makes it much less desirable for either home or business users.
The devices on this page represent the best among their respective categories.
The Seagate BlackArmor 220 is a good entry-level NAS server for small business and advanced users.
Seagate BlackArmor 440 is a workhorse NAS server that combines the currently largest possible amount of storage with an average number of features and performance that could be better.