My kicker is tied in so I don’t have the exact same application on my boat, but in running other boats from the kicker, I can tell you that it really depends how close to your face you can get that thing. At the same time, I like running split screen when trolling of almost any type, one view on the map chip, the other on the down-sonar. Your map view is limited on a 5″ screen, so I’d go larger there if at all possible. This is especially true on bigger water bodies with larger and more complex structure. I don’t think you need an LED flatscreen back there or anything, but a 7 – 8″ screen seems like a sweet spot if you can afford it.
Joel