At Sweden's show last weekend, I spent a little time chatting with Charles Jardine. He was tying flies and also exhibiting some fine casting diplays.
Amongst other things, we chatted about the use of jig hooks and the advantages they offer the fly fisher - both for trout and grayling fishing. He clearly explained the benefits of using jig hooks as he saw it, especially in terms of added movement of the fly through the water.
Charles took pen to paper to help discuss the merits of jig hooks over the traditional nymph hook:
Certainly when lifted as it moves with the current, the fly moves on its fulcrum and emits a very life like movements. There is much experimenting to be done here I feel.