I don't think that anybody will tell you there is a "correct" angle at which to sharpen you're knife. It really just depends on how you intend to use it. I just got finished sharppening a #15 using my lansky kit. I was going for piss sharp so I used the closest angle which I think is like 19-17 degrees. Now some guys will say that an edge that fine won't hold up well to general use, and they'd be right for the most part, but this knife is not for general use. Also, it takes a lot of work to reprofile the bevel to that angle from the edge that the manufacturer puts on it. Most of the knives I use daily have about a 20-22 degree angle. My numbers may be off so thats the 2nd hole out in the clamp. The nice part is that once I've reached the bevel angle that I want, I typically don't need to use the kit to maintain the edge. Just touching up with the finest stone by hand or stropping will keep you in good shape.
p.s. I use all my GECs. They keep a great edge too
