Summary: I got this about a year ago and the setup of my 4 drives with 1 TB each was seamless. The web interface that needed to use in order to setup the 4 drives as a RAID-5 was somewhat unintuitive (which doesn't matter too much if you're a technical person). Was bothers me is that the throughput of this device is very low. I have tried various configurations with various client computers and network hardware and the best I ever achieved was a mere 8-12 MB/s on a Gigabit LAN.
Summary: Pros: Set up from new disks was fairly simple. Sturdy chassis Low power consumption Good web setup utility RAID 5 support Easy to mount in Windows Cons: Could never get Linux (Ubuntu) to automount the NAS. Only accessible through network locations. Sorta slow. Get ~2.4MB/s transfer rates over a 100 Mbps LAN. Couldn't reuse existing disks from an existing RAID 5 array. Forces you to format the disks. Presumably, if the NAS itself dies, you're SOL.
Summary: The device has NEVER successfully formatted a single drive. Maybe there's an undocumented feature like a "Work this time, really" button, but I couldn't find it. This NAS has a lot of potential, but whether the firmware is inadequate, the hardware is poorly installed, or something else is wrong, it behaves like a sophomore engineering student's test harness. The only consistent performance with the device is that if will always fail to format.
Summary: If you're looking for a cheap NAS to store some data/backups where speed/performance are not in play, this may be enough for that. I have this NAS for over a year now, as well as a Synology 411+. I'm using this NAS as a secondary backup, but even for that I find that the data transfer speeds I get out of it are in the order of a poor 100Mbit connection (i.e. ~8MB/sec).