Best Gas Truck 4 Pulling

I had a 2010 Tundra and it pulled exceptionally well and it performed great with my old trailer and the current one. We usually travel with another couple and they have an F250 V10 and pulling the mountains the Tundra kept pace, that being said I did feel the trailer behind me more often that I would have liked. A few months ago I bought a 2012 Ford F350 6.2L and the difference with the stiffer suspension to handle the weight makes a world of difference and I am getting the same mileage as the Tundra did. If Toyota would ever come out with a Heavy Duty it would be a tough decision then.