There are so many factors that go into it, including wheelbase, type of suspension, gear ratios, engine horsepower, breaking ability, type of hitch, even some of the seemingly mundane items like whether or not there are extendable tow mirrors, etc.
I chose my 5.7 liter Toyota Tundra based on the following:
1. Price ($25k +/-) vs. about $35k for most of the 3/4 tons;
2. Diesel was headed for $4.50/gallon or more in 2008
3. Wheelbase was longer with the 8 foot bed on the Double Cab vs. short bed on the crew max.
4. ability to put one of the smaller kids in the front seat between two adults in order to keep the bickering down (that is the bickering between the kids, and the bickering between the adults!)
5. Extendable tow mirrors (I like to see behind the trailer)
6. Fact that our trailer maximum weight is under 7500 pounds, typically around 6500.
7. The truck gets decent gas mileage when used as a daily driver
8. You never really know when you need to might need to use the uncontrolled accelerator excuse to avoid a ticket !
I hear ya on the whole decision, there is no perfect choice and I felt like I needed a shower after leaving the showroom, but we have a serviceable truck that can tow our trailer and fit the kids in. And it got me to the Fort and back with no fatalities. Very comfortable ride too.