I'm at 113 coins per hour now. You're right that it is slow going but I'm seeing a decent increase in earnings per week at the moment.

And if I do some stuff on the offer wall then it gives a nice little boost to earnings. I had around 500k gems at one stage, I think I sold them all too early at around 10 gems per coin. But it gave my hourly earnings rate a real healthy boost once I upgraded everything.