I asked support why I seemed to be getting half of what I should be getting based on the hardware and their response was as follows:

"Dear Customer,

Thank you for contacting us.

Many S17 miners have run more than one year, hashrates are less than theoretical and many miners are offline, we are still repairing them. All users share the total hashrates.

S19 is better, are all brand new miners. Sorry for all inconvenience caused!"

So basically without getting into all of the funky math, they are openly admitting that their claims on potential returns are false. There's nothing to indicate whether you are buying (hashrates from) a used or new S17 device.   

As of the time this was written, the S19 has an amortization rate of over a year.  Since they start to break down after a year, you will never see a return. 

The majority of the comments in the last two pages indicate that payouts are no where close to what is advertised regardless of the coin or hardware. Digging through the discussions also reveals Hashnest and Bitmain  are owned by different people even though the site makes it appear that they are part of the same company.

Anyways, if got here via Google, this is my Hashnest review and experience with them.  It's possible that everyone posting here who is having issues with returns is an outlier but I would say it's not a good idea to engage them as a retail customer.   Maybe things have improved since this was written but try before you buy if at all possible.

I hope this does not get deleted.  It took a while to find this forum and some honest feedback.

Hi - new guy here.  What sort of BTC payout per TH have people been getting the past few days? I just signed up and getting about 0.18 USD per TH per day.  Just looking to see if this is to be expected.  Thanks