When we built our Duffy 33 I was offered the option of adding thrusters. I figured they're just another maintenance item and also add weight to the boat.
We previously owned twin-engine boats where docking was simply done with the gears. Needless to say my first few weeks with the single engine Duffy were comical when it came to putting the boat into either of our slips. With some practice and added time on the boat I;m starting to figure it out and like the fact that I didn't spend the extra money for a thruster.