From my own perspective, I can certainly say that all cloud mining services are pure scam.
Do not even bother to put a single dollar in them. Basically if you take a look at most of the cloud mining services that ever existed, you'll find lots and lots and lots of people screaming scam scam although they were warned before it not to invest.
Just think about it. It's a business. And in order for it to make them money, they have to rent it out for more than how many coins it makes in order to pay for electricity, office rents etc. That's literally just plain logical thinking.
Some of them don't even have the mining equipment ready. So what do they do ? They use your invested money to buy themselves the miners and then pay you even less. But how do they do that ?
All of these services offer "long-term investments" which gives them the appropriate amount of money to buy equipment.
They mainly work on selling prettified words and unfortunately you believe them. They'll tell you that you actually will make profits and even try to prove it to you with maybe some reviews/graphs or anything else. BUT DON'T BELIEVE THEM !
You might see good numbers for the first or two months but it then starts going down. You won't make any profits out of it. And if you're lucky enough, you'd get your capital back (which might not even happen). What guarantees that they even stay until next year ? NOTHING.
I'd say, if you want to earn from mining, do it yourself. Buy the machines (but be careful as there's a lot of fake stores around so first do your research and do it properly) and set them up yourself.