I'm looking but one used. Wondering what you guys think of this unit? Is the side imaging as good as the models that are coming out now? It doesn't have down imaging. Would it be better to buy a new unit that's much smaller but has both DI and SI? I will be primarily using it on the finger lakes for walleye, perch and bass. Occasional trips to Lake Ontario as well for trout and salmon. Any I go helps. Thanks.