GMC 2500HD instead of a Ford F250 for our 5th wheel...

According to a GM engineer the GMC's are a little quieter and a better trim level, comparing a WT to a base Sierra in the HD trucks. The GM trucks have independent front suspension which helps with a more comfortable ride vs the Ford truck. The truck in my signiture rides better than my bosses $60K F350, empty or loaded.
I would definitly skip the 250/2500 series an buy a 350/3500 series truck. We have a lot of GM 3500 gas trucks avaliable in the Northeast US.