So here's my 2 cents;

I personaly see all cloud mining platforms as scams, or fraudelent at best.
And here is why; cloud mining platforms are business like any other, and they sell a service, which roughly translates to:
- buy a contract for X, and receive Y amount, ROI Z guaranteed.

But ask yourself, if Y+Z are more than X, as all of them promise, why sell the service at all? Why not just mine and make more than X will provide?