I've used it for bass on Bull Shoals and TR with my buddy. Get on a point and you can see each fish, their depth, and behavior. Last March I watched a ball of thousands of shad on a point on BS. Occasionally 5-10 of them would separate from the larger group. As soon as they did, three or four bass would ambush them from below and just annihilate them. It was so cool just to watch. We caught quite a few, as well. You could see, say, an A-rig coming through the water in relation to where the fish are. I've noticed with A-rigs you think it's deeper than it is running. That is valuable to see.
You can even see a jerkbait on it, how deep it gets in certain water temps, and fish that come up to it and get oh-so-close to biting. It's really a hell of a tool just to learn from.