I pursued a review on this in some woodworking mag a bit ago. It seemed the main feature was the ability to see thru the disk to the edge being cut via a series of cutouts in the disk. I am not one to use a power anything for sharpening tools (other than a hoe or shovel) I am concerned with too much heat transfer and a failing of the temper...
There are those who can use power sharpeners to great success, if you are one I would go to a Woodcraft store for a demo before parting with that kind of wampum...
