Lss1 ducer with lss1 module, graph is a gen2 12, speed 1.2mph (ducer on the trolling motor) Both ducers were on 455 for comparison, I didn't use 800 because it's cone angle was too small for shallow water.
Lss2 ducer on the transom straight into a gen2 12, same speed as above. Unfortunately, I had the contrast off jus a tad during this experiment; but the lss2 was the sharper image.
You can use the lss1 ducer into a lss2 module, some say it's better and some say it's not. The adapter is a ploy to make money, it's supposed to be a "filter" and yet again some that have bought it said it made their images better and some said it was a waste of money. I have learned to experiment with all of my options and to decide what I think is the best.