What are your preferences for a diamond dresser for surface grinder wheels?

[HMF]

Simple block with a diamond point or something that can be extended vertically? Any particular design or model you prefer? What diamond size, length and shank diameter would you choose?
What about your favorite bench grinder wheel dresser? What do you like to use for an 8" one?

Some people like diamonds. What is your preference?


Thanks,


Nelson