You'll always get ROI, sometimes positive and sometimes negative. If you get negative ROI with HF and have miner protection you'll receive the additional GHs. So I don't get what the KnC won when their machines will never get positive ROI and they don't have miner protection. Well see who won in a few months when miner protection kicks in.
Miner protection is BS. The more GH/s hashfast distributes, the more difficult will be to have positive ROI.
The only possible miner protection is to sell the fastest and most energy effective machine in very small, limited batches. I mean batches of 300/500 machines, as Avalon did with batch #1.