It is annoying how expensive NAS devices are (without hard drives)
For many, you can build a PC that will support more drives, the same raid methods, and have significantly better performance and offer more features, all for much less money than a dedicated NAS.
for example, on an old system that I use as a NAS/ server/ DLNA/ game server/ torrent box (sometimes performing many of those functions at the same time) the AMD 64 3200+ system, can read and write to an encrypted partition at around 110MB/s (max speed of the 7200RPM drive)
If I want the transfer to also be encrypted, then I can SSH into the device and perform the transfer and the speeds will still be about the same.
I mainly use the DLNA function for streaming media to my tablet (since no transcoding is needed (tablet supports pretty much all of the popular formats as well as soft subtitles)
I can usually have a backup going while at the same time downloading a torrent, and hosting a left 4 dead 2 server
and still have the backup go at around 100MB/s + (I have multiple hard drives, but I did not set up raid )
The CPU rarely clocks up to it's full speed.
Not sure about the load power of that NAS box but I am sure that the old PC uses more power, but overall, it does more, it offers better performance, supports 4 drives (and can be expanded if I get a cheat $12 2 port raid card, (I can add up to 4 of them) (I can also add a USB 3.0 card since a full sized pci-e slot can also support x1 cards though I will lose a standard PCI slot since I would have to install a regular PCI videocard)