software is also open source
You can get it here: http://sourceforge.net/projects/dsgpl/ for various ARM and x86_64 archs...have not yet set up a virtual machine to try things (on the todo list - raspberry pi?)
I own a 211j box. Not very powerful, but energy efficient and quiet with low rpm seagate disks 2TB (http://www.amazon.co.uk/Seagate-ST2000DL003-Barracuda-3-5-inch-5900RPM/dp/B004C0WVP6/ref=sr_1_4?ie=UTF8&qid=1386092562&sr=8-4&keywords=ST2000DL003-9VT166) in a raid1 conf.
The reason is that I host my mail server and need the box up at all times. Although it has a spam killer, I use the various aliases I create for different sites requiring registration to cut the problem from its root if they pest me with unwanted mails.
DLNA server for mkvs (no problems at all) to my WD Live box to the TV, streaming my mp3 collection to my iphone/work pc, and Time machine for my backups is what I use most, although I use quite a lot of features - like backing the box up to Amazon's Irish Glacier server.
What makes me a satisfied buyer of it is the little amount of time I spend maintaining everything I use. That is why I would recomend it to anybody who does not have the time or the inclination to set up a custom box for similar functionality
The various packages available for it (http://www.synology.com/en-global/dsm/app_packages) work quite well, plus there are other non official repos too.
Must say though, that I have found more uses for it than the box I bought can handle, so my next buy would be a more powerful version of it.