my dealer also highly advised me to turn it off during off road conditions. I went over a good size speed bump not straight on and yellow lights came up on my dash board and funny noised came from down below my leg area. I thought for sure they would trip.
I traded in my Tacoma for my new 4runner, both tow my 3500lbs boat just fine. The ride in the 4runner was obviously smoother than the tacoma. As far as power or handling while towing I would say they were very similar.