The more you use the better you read. If I am actually searching I run full screen SI and flip over to map periodically to make sure I am where I want to be relative to structure - I can see much more detail that way. Once I see what I am looking for I switch to half 2D and half map on the next pass to get more detail and drop electronic markers. You learn to identify fish by the color and shape of their returns on 2D and their relative position in the water column. 100%, no, but most of the time you can make a good ID. I normally have just 2D and map up on screen when fishing unless I am after striper/hybrids and want to keep an eye on the schools while trolling and will flip back and forth. Shortcut buttons are set to full SI, half map and 2D, and the last to map -DI-2D split 3 ways. This works for me.
Plug, once you run one of these newer units you can’t go back...they are truly great. Do I have to have? No, but I don’t really need a boat either to catch fish...but searching for and dialing in on them is half the fun.
Mike