i think its legit - so no scam - but it is a high risk investment, esp when you mine BTC because genesis can end the contract if it is not profitable for them. I am mining with genesis since about a week (BTC, ETH, Dash and XMR) and I am quite pleased with the results - I also read a lot about them before and I think you can very well earn money, if the market does not crash or difficulty gets too high (which nobody can foresee). I recommend to try it out, but do only invest money that you do not really need...