Hi genec, seems like we have a lot in common. My name is also gene C and I was also born in 1944 and I just bought the 798 unit. I can't really answer your question but as time goes by I hope to be able to get nice screen shots of fish and structure. I've only been out twice with my unit and at first I was feeling a little let down by what I saw. Then by the end of the second day I started seeing things that were there that I hadn't noticed before. I was looking for some great shots like you see in the advertisements but like you said most of those are shot on the larger screens and are of easy to see structure. To help me identify what things looks like on screen, I rode through a marina where I could see above water pilings, docks, and boats and then looked at what they looked like on screen. I toyed with the settings a little to see how to get better views. Since I only fish shallow water, usually 7 to 8 foot deep, I tried using a 30 and 40 foot setting on the range and also used only viewed one side. That rally makes everything larger and easier to see. That was on my first trial run. My second trip was to go fishing and study the unit and pictures in a real fishing situation. Knowing where there were underwater stumps I headed in that direction. I was able to find them easily with the unit with all setting set set to default. I learned to distinguish shore line weeds from the open water along the banks. I even saw a few large fish which showed up real nice (it's easier to see their shadows first). Sorry to say I didn't find any concentration of fish on the finder or on my line but even after only the second trip my confidence with the unit is going up. I think it's a learning curve that we just have to go through. I'm sure a TV size unit would make everything nicer but for now I'm satisfied with what I could afford. I watch some video's on line that showed how to tweak the units so as to be able to make object stand out more but I don't know there exact location now. I'll have to look them up again because I'm sure I can get better views than I'm getting now. Like I said I guess we'll just have to go through the learning curve and I think I'll be happy.
"gene"