Their rate is 3.6 btc / yr thats correct? If so, its worth imo, but a lot of people say its a waste of time and they are very hard to handle and setup, idk if they tell this just to discourage new people get into mining

Im planning to get 5 Asic R9's, please note that I have Free energy, what would be my costs besides the miners cost?

Are they really hard to setup? They have a decente life-time?