hashflare is legit so far
roi is about 3 months and obviously the higher the investment the bigger the profit
only invest what you can afford to lose
In the meanwhile, with such a high price 2.2 USD per TH/s and such a high difficulty rising rate 18% every 2 weeks, the ROI can NOT be only 3 months, anyone who want to get involved should do some more precisely calculation. That is my advice for now.