Hey, Walt! Good to see you on here! I have to admit I have zero experience with the Wood Duck with the shorter shaft. I do have 22 years of experience running a 23hp Stump-Jumper on a 15' 11" very wide Mirrocraft semi-v for hunting, fishing, and trapping. I love it. Last Fall I put an old 5hp Go-Devil on my 14 ft. Herters Duck and Goose skiff and love it but will be switching the engine from the old Briggs 5 hp. to the Predator 6.5 with the electric start kit. The old Briggs was a bugger to start and I am fed up with it. With my wrist, arm, and shoulder problems I need something easier to start. When it Did start I used it a lot for duck hunting and it pushed that skiff through the slop I hunt in just fine.
My most common advice to guys who ask me about the longtails is to not expect the speed and quick maneuverability of an outboard but it will get you where you want to go. It takes some practice handling the motor when you get into the real loon slop and weeds. You will reach the point of needing the pushpole for sure, if nothing else, to get the boat turned around so you can run it out with the motor.
A lot of duck hunters ask me about them and you will find they are weight-conscious. Too much weight in the boat will bog it down for sure. I usually tell guys to step up on the hp rating of the motor if they plan on carrying a lot of weight. You may want to consider the same. Not sure of what you are planning on spending but you may want to to take a look at
www.stump-jumper.comMost longtails have a safety cut-off tether,,,use it!
Good luck!