These thing look sweet i hope to have one in a week or two i like having a stand along controller a lot more then a built in one .
It is a big bonus as far as if anything goes wrong. If something goes wrong swap out easy with another RPI and no special hardware is needed. Say you brick a S7 controller then it's not something you can buy off shelf at local store to replace like a RPI.
Also the image I posted from BlockC above is very good. You could put flash it on a SD card and having a new controller running within minutes.