We bought our truck used and the tailgate was the poster child for 5th wheel tailgates. He pulled horse trailers and neglected to lower the tailgate once, and once was all it took.
We replaced the badly dented tailgate with a notched tailgate and I'm very happy with it. It means there's one less thing I have to remember to do. And IME Murphy will step in when you least expect it, so the fewer things you have to go wrong, the better. Also we have had to hitch and unhitch at an angle before and we would punch a hole in the front of the fifth wheel if we had to have the tailgate lowered since the trailer is close to the rear of the truck.