Although I have owned a couple of fish finders with side imaging on two different boats, I have not used side imaging very extensively. I am not a very technical angler, nor am I very patient with the technical side of fishing. I believe fishing should be a fun activity, not a science. I know, I know, it’s more fun when you use your electronics to help you catch fish… I use my electronics mainly to give me an idea of where fish are, and how deep they are. There’s been times when side imaging has helped me find structure and fish, but the following fishing sessions were not always successful. I think my problem may have been going back to the exact spot where I saw the fish on the side imaging. I've always struggled to go back to those spots after I see them on side imaging. With 2D imaging, you only have to worry about how far back it was. With side imaging, you have to think about how far back and left or right. You can mark a GPS coordinate on your fish finder but you still have to go back and find that point. Too much work for me...
Linking the trolling motor with the fish finder would solve much of the problem with going back to s pot you saw on side imaging. You can mark the spot where you saw fish, and have your fish finder make your trolling motor go to that spot. That’s the next investment on my list. You will need 2 components for MotorGuide: the MotorGuide Gateway Kit and the NMEA starter kit. This thread has good information on the topic:
http://www.bbcboards.net/showthread.php?t=783409
Size does matter when it comes to side imaging, or so I have heard/read. Most people are saying 9” or larger. I started with a 7” screen. Side imaging is pretty small on it. The plan is to acquire a second 9” or 12” screen next year.
PS: you all must be wondering how I have all this information?

When I research things, I email myself the links and relevant notes, so I don't have to do it again.