I don't know a lot about any of the Humminbird Side Imaging units. Please help. Do I understand right, that there is a software upgrade that converts the SI so that what you see on the screen is easier to understand? If so, are all models upgradable? Even the 798ci SI? I know the screen is small on the 798 but if I were to get one, it's the only one I could afford. Any thoughts?
