I tow a 33' fifth wheel (16k GVWR) that was weighed at 13.8k loaded for camping (no water and waste tanks empty). I am a few hundred pounds over the GVWR of my '06 2500 4x4 CC Chev. Duramax but well under the axle ratings. I have pulled through the Black Hills of South Dakota and been to Arizona from Canada once with no issues. I have towed tent trailers, travel trailers and smaller fifth wheels so I know something about how trailers handle. The smaller fifth wheel was pulled with a 1/2 ton and it scared me a few times when the trailer seemed to be controlling the truck. I have never felt that I wasn't in control of my load with this setup. That being said I am a very defensive driver and travel under the speed limit and allow lots of room in front of me to stop. I'm in no rush to go up or down a hill and let the Allison do the work. I come from Sask. Canada and it has to be one of the windiest places on earth. The wind cuts my mileage but doesn't push me around to bad.I have not had to make an emergency stop so I can't speak to how that would work.
Brian