I'm a customer, and I will say this, though their service is probably the best, you cannot ROI anymore. All those front page mining calculators do not take in the Difficulty increase over time, so they produce false results. You could go and try looking for a different solution really, just not SHA256. My opinion thought, your bitcoins and your choice in the end.
I didn't even know there were BTC profitability calculators WITHOUT the ability to project difficulty increases in your calculations. Most calculators have this and the "default" number is normally set between 20-30%.