I've been a customer for 8 months now, oneminers is real, they operate multiple hosting centers, with legitimate partners and many customers.
Many comments on this page are not aligned with reality.

Many of the red flags mentioned are caused by exaggerated or false claims made to lure beginners or naive customers.
Other red flags are caused by the intentional low legal footprint of the company when the authorities knock at the door.

In reality this could be a great service, they do many things right.
The largest problem is that you cannot configure your own pool account, by company policy, not a bug. The rewards go first to the OneMiners wallet, and from there they give you a fraction. The claim is that you get 100% of the pool rewards, simply not true, easy to verify (compare one miner rewards with any of the established mining pools), so the actual model is rewards sharing.
For BTC the range of what OneMiners "takes" from the rewards is 5% to 20%, you will never receive the full rewards. For other coins it can be as bad as 50%.

Let me say that more clearly, at any point oneminers can decide to take an arbitrary amount from your rewards and there is no recourse. Their explanation for the gap is "pool luck" which absolutely only fools beginners, all pools you can choose from have the same "bad luck". This meets the legal definition of fraud...

This questionable company policy (aka rewards fraud) prevents me from recommending this service, fraud policy cannot be fixed, it is not a bug.