The bottom line with any fly like this is that the rubber legs give it action. That slow, tantalizing undulation motion, when mixed with river currents, brings the fly to life, and makes it a very effective attractor pattern. Like the original Girdle Bug, this fly is about profile and color, but the newer materials used to make the rubber legs is what gives it the pop. I'll fish this pattern as my top fly on a double-nymph rig when I'm merely prospecting and don't really favor a specific nymph pattern over another. I also fish it as a dropper on a dry-dropper rig, especially when stoneflies are hatching and the water is just a tad off-color. As is always the case, trout are more inclined to eat a fly that's well-presented, with a drag-free drift, than some spot-on replication that looks good in hand, but not so hot under the water. Never underestimate the power of a good, simple, ugly fly.