If you're thinking about buying one to use as a regular Linux machine, don't. It's ridiculously restrictive and the whole system breaks if you try to replace the preinstalled SteamOS services with anything else, not something I would have anticipated were this actually "just a Linux PC" like everyone keeps saying. I'm done messing with it and having to constantly reimage.
If anyone's interested in buying it off me, IM me. I'll give you a good deal for the 512 GB deck and the official dock :P