I always say get the largest screen size you can afford but image quality is important as well. I'm sure both units have good points. Go to one of your local big box stores that have these units in stock so you can see them both too see which one fits your needs the best. A 5" screen is really small for side imaniging. With HB Autochart you can make your own map on those small lakes you fish. Have you thought about buying a used unit from someone on here or BBC, I've seen some really nice units with larger screens in that price range that should work well for you. Good hunting!