A lot of my crappie fishing is spider rigging at very slow speeds. I was looking for a better depthfinder. Am I right in thinking that the Down Imaging would not show optimum images at these slow speeds. I was thinking that the split screen on the 570DI unit would allow the best of both worlds. The regular sonar to show fish and some structure at slow speeds, and the DI to show better views of structure at higher speeds. Am I right on this and are there any other units that have either split screen views or at least offer both options. Any info or suggestions will be appreciated.