I do not know much about the full line of Garmin Strikers, but for the purpose of management and research of my camp association lake, I wanted a bottom depth mapping capability. I decided last season to try the blue castable striker as an inexpensive option. I drop it in the water and tow it floating a few yards behind my canoe with its provided sturdy but thin braided nylon tether line.
It communicates with an app via Bluetooth on my phone as it displays the lake bottom profile with a depth scale in a live video as I slowly paddle along. it displays the bottom profile including obstructions, and it definitely indicates what can only be fish at various depths below me. I am happy with what it does for the price. I should be able to save the profile map in a file, but have not figured that out yet.