First I want to say the pic from GFL looks to me like the gain/sensitivity is set correct - if anything it could use a tick more - sometimes i will deal with some surface clutter for more gain - for a 15lb salmon you dont need alot of gain - for perch close to the bottom- more is better, or for seeing the thermocline, or if your looking for baitfish that are not in a huge ball/ i.e. loosely scattered - as per the question by Salmonquest GFL's unit does not look to be at 100% gain. You should not need 100% gain. Most screens would have way to much clutter to see anything. What I do see on the pic is the dark blotchy marks around the fish in the center of the screen. Also scattered blotchy marks elsewhere on the screen. I dont know for sure what it is, but my lawrance set on auto will not have a lot of that for a while then when the screen gets real dark, more so than GFL's pic, we smile. Seems fish like it. Could be a bunch of water fleas, temp change or loosely schooled bait, what ever we like it. When the screen gets dark like that continually its like someone turned the gain full bore. We will make a few passes through that stuff. GFL's pic has little surface clutter meaning the gain is not to awful high but does show the blotchy stuff meaning it is high enough to show the detail you want to see. Fish symbols - do not use this feature ever, the only time you should is in weeds to seperate weeds from fish - that is what the manufacures say- my opinion - you better really know your sonar before you can tell the diffrence because I believe weeds will also show as fish symbols, not to mention air bubbles and crap suspended in the water. I have seen thousands of fish in fish mode, never caught one, the fish I seen with arches, well atleast I caught a few. You will never see a fish symbol come up to your bait, you will see arches come up and sometimes a pole goes off. Gain/sensitivity - the older units you had to shut off the fish symbols and turn the gain up manaully to really use one correctly. The new units you can shut off the fish symbols and still be in auto mode for the gain, in auto the sonar will work very good as far as gain is concerned, especially on shallower water 40 or less but still works fine deeper. I fish no deeper than 90'. I try to turn my gain up 2 or 3 notches? If i go more I get to much surface clutter. I would say it is close to 90% but I would have to look to be sure. If I am busy setting poles or whatever and forget to adjust it up, I dont worry about it. Thermocline shows well in auto or with it turned up, at up to the depth of 90' and more I am sure. The older units that you have to shut off the fish symbol and go to manual you will almost for sure have to turn up the gain to see it. My 4 cents worth. Hope it helps.