Has anyone used any of the more economical side scan sonar systems currently available? Deep Vision, Edge Tech or the Hummingbird 1100 serie

Yes, we have been using the DeepVision DE340 system during the 2009 shipwreck search season. It has performed extremely well in locating shipwrecks here in the Great Lakes, St Lawrence and Hudson River. A collection of images from these areas appears on this website. See DeepVison Side Scan Sonar Images.
The additional feature of mapping of the search area on nautical charts display on the computer screen in real time is a great advantage in knowing that you have completely covered the intended search area. Also, being able to enter into the program a cable layback provides a more accurate position to detected targets and with the DeepVision program when you place the cursor on a target it is the real position. Some other manufacturers only provide the position down the center line of the display screen. Email me for any specific questions that you may have on the use of DeepVision Side Scan Sonar. They have one of the best value side scan sonar units on the market .