So my brother and i are going to get a 10 or 12 SI helix and dont really understand the difference of the chirp to the dual. Either way its a good chunk of change but we are willing to spend it if its worth it. We are going from a old old gray scale type finder and will have this one for awhile. We wont have 360 or i pilot for now but could later. Please explain what we will or wont gain from the chirp sonar if we go with the 12. That is our biggest hang up right now. We could live with a smaller screen but if its better then we will get the 12. If anyone knows of a video that would be great. Thanks for any info!