Just take a rapid look at the charts of poolpicker and you'll understand why you'll never break even with these scam asics.
Gridseed is about to flood market with thousands of gigahash mining power. Even with many alts to mine, there's no way you see a positive ROI.
They are selling them 3 to 4 times the price they worth...
In less than a month we'll be sub 0.001 btc/mhs/day if not 0.0005.