Pros : I purchased three of these for our stained glass classes, and they get a lot of use. They seem to be better engineered and stand up to student abuse better than the Wizard grinders we also use.
Cons : Top is hard to get off to clean the water reservoir. Twofer bits don't fit these grinders.
Other Thoughts : Studio Pro bits are the only ones I have found that fit. This brand only come in really coarse (Fast Bit), or really fine (Standard Bit), there is no grade in between.