A great grinder at a good price. You NEED a great grinder to get even decent espresso, and Rocky fits the bill.
Positive Product Points
Near perfect consistency.
Great control over the grind.
Extremely solidly built.
Fairly easy to take apart, clean, etc.
Negative Product Points
Doser is not adjustable.
Doser has a pretty bad assigned dose size. (6 grams or so).
Plastic parts are cheaply made, overall.
Not great fit and finish of plastic lids.
Occasionally gets clogged.
I paid about $170 for a demo model. It came very poorly adjusted, because the techie at the place that sold it to me had taken it apart to clean it before shipping, and hadn‘t really put it all back together that well. Called the shop, and they walked me through taking it apart and adjusting it. Very easy!
Overall, I would say that Rocky hits a price/performance sweet spot. It has the internal workings of a Rancilio MD40, so it performs nearly flawlessly in its main task: grinding.
To the extent that there are any problems, they are all secondary in nature. The lids don‘t fit tightly, and the coffee occasionally doesn‘t feed properly to the burrs for grinding. An easy fix, with a stir of the beans in the hopper, but mildly annoying nonetheless.
I will probably get an MD40 or another similar grinder eventually, but I have no doubt that I will continue to own and use Rocky nearly forever.
My biggest gripe with Rocky is that I think the doser should be adjustable. The perfect shot is neither 2 pulls, nor 3. It is 2.5 or so... I wish I could adjust the amounts!