On my 22, I have a short shaft 5 hp (15") mounted on a homemade fixed bracket that has about 6" of setback that off sets some of the water flow problems of having a short shaft mounted on the transom that Bob speaks of. I can even move the boat in reverse.
A buddy has a 22 with a transom mount long shaft 5 hp and we have run the kickers together and the performance is very close. We have not compared reverse performance. I would suspect that with his prop below the bottom of the boat, he would have more control and speed in reverse.
If I remember correctly, I am able to get 4-4.5 mph at half throttle and barely 5 at full throttle. I have a quick snap on and off steering rod that connects to the main motor, but I have read that others are able to lock the kicker and steer with the main.
Some have the full remote control setup for the kicker with electric start, throttle, steering and shifting. Those setups are much more expensive and are usually not readily removable.
Our motors are single cylinder motors and easier to move on and off of the boat. The higher hp motors would be 2 cylinder motors, smoother running with more power, but heavier to move.
I think that there is not a right or wrong decision on this subject, just what ever works best for your needs and boating conditions.
Best of Luck.
