Not strictly relevant I know, but I rejected a take off in a P68 at MTOW years ago after I found I couldn't rotate it. I'll never know for sure but it was probably the autopilot being engaged or severely mistrimmed. Still gives me a cold sweat when I remember how I felt when I went for the brakes and almost nothing happened. As the end of the runway approached I pulled the mixtures and dodged the runway end lights. We stopped about 10 feet short of the perimeter fence and I managed to start it up, turn it around and taxi back to the runway and then to the apron without anyone noticing as it was a small uncontrolled GA airport.
It does concentrate my mind on every takeoff I do in the RJs I fly now though...