I prefer the arches and the little fish. The arches seem to be more reliable.
As the reat have said, I use mine to see bottom structure, but, I also want to see fish and know where they are holding, specially when deep nymphing. If they are 1' or 3' off the bottom, I need to know that. Doesn't mean they will take what I have to offer, but it will put me in the ZONE. I once saw a fish at 15' deep right next to my brother, so I looked at him and said, "Watch this" kidding around, I had Type II that I had let a lot of line out, cruised past him then started to strip and BAMB! "Fish On". Had him convinced that I could target fish.....I know it was just luck
Check out this COLOR sonar: Humminbird 343c Fish Finder Combo