I have caught sockeye in the Fraser, the Kenai, the Russian, and the Little Susitna. I agree that clarity and "water size" plays a big role in whether the fish bite. The Little Su is a smaller river, clearer river, and I caught multiple sockeye with a sinktip using the wet-fly swing. The takes were very perceptible -- there is no doubt the fish bit. Ditto on the Russian.