Wow, this is such a cool forum. I came on this thread with basically a dissenting view, and did NOT get burned! Thanks you guys.
NotYou, the method I learned from Cumpianos book is simple. If you run the plane parallel to a middle line on the FB, you create a cross section of a cylinder. If you run the plane parallel to the edges, you create a cross section of a cone, or compound radius. I have a nice 22" jack plane from Grizzly, only about fiddy bux. The thing about a compound radius is, any amount of it is a big improvement over a normal radius. I'm fairly certain that you can eliminate fretting out just as completely with a somewhat less than mathematically exact compound radius, like you can easily plane by hand. I'm just saying that the radius is probably not as accurately calculated as it would be by machine. I still stand on the idea that the plane makes a flatter, more accurate, better feeling FB than a router.