Also, what good is the miner without this 'control board' .. what does the 'controller' do? is it simply a raspberry pi or like?
As I understand it, you can use the miners with any linux, if you compile/use (customized) cpuminer od cgminer.
Even a Windows PC should do the work.
The board is a small ARM based linux computer so you dont need any aditional hardware.
This is my understanding.
You are correct, it is an efficient way of mining, also with what people have developed for windows so far will not allow you to dual mine only one or the other