They are very efficient motors for their weight. They are two stroke, so they might smoke a little depending on what oil you mix. They are not fuel efficient compared to V6 or V8 auto type engines.

A SJ should be fine until you have a loaded boat/heavy boat. In this case, you can't beat a V8, but if your boat isn't that heavy you may do just fine with a SJ.

I'd go for a test ride with your fishing partners (for weight) and decide if you like it or not.