not worth it, like any cloud service, roi is too far away, but you could try to purchase some GHS to see how it's go
also i really can't udnerstand your first question
is low ROI but very GHS should will buy .
First question:
how many years will exist hashnest ?
i think it's better to not buy, not worth it
no one know for how many years hashnest will exist, they could close tomorrow or live for other many years
basically he don't mind slow roi, and he want to know if hashnest could live long enough for him to make roi