the problem is the price of this device ... you can build an atom motherboard+RAM+SSD and 12v 10A supply for less and buy an U3 after this (on the same supply).
or you can even mine altcoin with your rig already built and settled nicely with your gpu card and be good already, there is no need to waste money on something which is dedicated only to mining
with my computer i can do much more than simply mining