Hey, that was something we also found. Also similar to HydroMiner.org
But here there are three very important differences:

1. You already spotted this, they have custom miners, which result in a better roi. On top of that, you are owning the miner, and not only renting it (so I understand)
2. They are an established company since 2015. Not starting just after the ICO
3. They have 3 other business developments, besides mining - bitcoin atms, payment systems and an Exchange.