Something more than "here's forty-six more stitch patterns you can use on the instep of your sock!" which is mostly what's left for me in the SKS book. SKS feels like one designer's take on sock construction -- granted, there's top-down and toe-up options, there's a couple of different kinds of toe options, but it still feels like one person's wisdom.

I guess I'm looking to deepen my understanding of sock construction.