Pro
More efficient than a shaft driven prop.
Video game - joy stick - steering.
Less space required in engine room.
Con
More maint. Annual haul out.
If hit something, more to lose.
I have had a joystick for a few years, and rarely use it because I was already comfortable with the sticks with maneuvering, and I didn't want lose that skill. They are a good selling point for people who have not had much experience, and the dealer will tell them they can now park a 50 ft. boat. Kind of scary, but happens a lot.
Eventually, most P boats, 40 ft. and up will have them, but personally, I don't think they will ever make it in to the main stream trawler market.