Good for moderate espresso machine, but it can not make fine enough coffee for a more sophisticated (>500) machine.
Positive Product Points
Easy to finetune, different grind settings (from coarse to espresso fine), Timer to define quantity, Price.
Negative Product Points
Not fine enough grinding for semi-professional machines (> $ 500).
Detailed Commentary
I bought this grinder for my Quickmill (2820) espresso machine. For this machine I looked for a grinder, but it was a hard way. The prices differ between $50 - $ 700 in th Netherlands. After a lot of research I decided to buy the Solis Maestro, but unfortenately the coffee was not fine enough. My espresso machine pushed the water within 15 seconds through the holder when I grind the coffee in the finest position of the Solis Maestro.
I think it is a good grinder if your espressomachine is in the $100 - $300 price range. Especially because you can choose to grind for a espresso machine or a filter machine. Besides it has a timer so you get exactly the quantity you want. Iif you have a more sophisticated machine (> $500) I recommend the Innova grinder, which I have at this moment. The grind produced by the Innova grinder is perfect for my machine and it can easily grind even finer for a professional machine. If you want a more extensive comparison between the Innova and the Solis Maestro, you can look at this site under coffeegeek reviews.
Buying Experience
I bought the machine at Bartolomeo (www.bartolomeo.nl) in Voorburg (Netherlands).
The owner advised me the Solis Maestro and was very kind. Although he could make more money with the Innova grinder which I initially wanted to buy, he advised me the cheaper Solis Maestro. After I used the machine, I told him that the Maestro could not grind fine enough. He wanted to adjust the machine for me, but I told him that I was more interested in the Innova. He gave me money back of the Solis grinder and gave me an additonal discount on the Innova and 1 kilogram coffeebeans for free. I think this is excellent service, which is not very common in the Netherlands.
In summary it is an excellent store, with one of the lowest prices in the Netherlands (look at the site to compare prices: www.bartolomeo.nl). Besides they can repair your machine in the shop during your visit. This saves a lot of time, because most shops send the machine to the dealer, which takes at least 2 weeks.