The maths just doesn't add up, the ROI on this unit is just not worth it.

Why not just buy 5 ANT Miners?

5 x 180GH/s = 900GH/s  - That's without over clocking.

That will set you back just under 5BTC (They are 0.99BTC each including shipping)  or at current exchange rates on coindesk $3155 or £1900.

They are shipping now, so no wait for your vapourware!

Ok, I know the ANT Miners will be burning more leccy, but if that isn't an issue I know where I would spend my money.

Investing in Bitcoin mining hardware that

a) You might never receive
or
b) When you do get it the diff has gone up to further increase the time to ROI

Is a mugs game.