I知 considering updating my fish finder. I currently have a Humminbird 561 black and white that came on my boat. I知 looking at the Humminbird Helix 10 SI /GPS combo. So my question is how important is a good fish finder? Is SI better the DI or what the benefits of each? I primarily fish Rend for crappie and catfish. So this is the lake it would be used on. So what do you all think?

Thanks.