I always wear mine when fishing alone, always when the big motor is on, and the majority of the time when fishing with someone.
Fishers is correct, if you can't get back in the boat in cold conditions, you might not make it. Always have your sure your cutoff switch is connected when on the big motor.
I'm about to get a new boat and it is coming with a ladder on it. Not a very good way to do a ladder on my current boat, so I have practiced with the tilt before.