I think you will find that most of the posts here will say bigger is better. This is true but you also have to live with the beast.
My half ton is maxed out with a 5000 lb. trailer once we are loaded for the road. However the rest of the year I enjoy the ride and improved gas mileage over a larger truck.
If I had to list the features I look for they would be;
โข Max Cargo, which varies with model and acsessories.
โข Horse power.
โข Towing package with all the coolers and gearing.
โข 4 wheel drive because of the places I sometimes go.
These are my criteria, everyone has their own based on their personal preferences.
Twenty six foot 2010 Dutchmen Lite pulled with a 2011 EcoBoost F-150 4x4.
Just right for Grandpa, Grandma and the dog.