finally it may come to cost of devices and with made in China miners will be hard to compete.
I think the success of BitMain chips is a serious threat to AM. Once they come to the mass production stage, I don't think AM can sell their cube any more without the new generation chips.
there is about 8 companies developing 28nm chips, so it will be real saturated market by next year.
but for now, I agree any devices AM might bring to market will sale at once. As it is shipped now, not pre-ordes.