I have never used a grinding wheel dresser before. As I start to do more turning and also try to improve my drill bit sharpening, I am thinking about getting one. My casual observation of other people's shops is that they are used by some people and not by others. I also see online that there is a wide variety of prices. I am just canvassing opinions. Do you use one? Do they do a good job? What should a person look for if buying one?