Thanks everyone,
To answer a couple of the questions:
With the BH sharpener I like to start on a very coarse stone. BTW, coarse and x-coarse stones are our friends, they save lots of time and who wants to spend hours sharpening heads??? Get them sharp as possible with the coarsest stone you have, then you can zip through a couple finer grit stones to finsh polishing/honing in no time. The stones we include in the kit are the same ones I use myself. Just about any 2 inch wide bench stones will work though.
You can touch up heads mounted on shafts with the BH sharpener but you'll need a bit of working room cause the shaft is gonna be traveling with the sharpener and BHD.
The knife sharpener is really a better choice for sharpening "on the shaft" because the stone is moving rather than the BHD and shaft. One important point though- Both sharpeners are honing tools. If you're sharpening laminated tip heads that require a lot of stock removal on the first "out of the pack" sharpening, it's a very good idea to get them somewhere near sharp with a file before going to either sharpener. Again just a time saver, and by using the file to hog the metal off, you're not asking more of the stones than they're designed to do.
Thanks again everyone,
Ron