I've got a crew cab Dodge and a Suburban. Both are gas engines. The Dodge is a towing beast, but the Suburban is the prime people mover. With the abiliy to seat 8, rear climate control for comfort, and an entertainment system, the old Dodge just doesn't compare to moving butts around town. ou ould get the same seating out of a Tahoe, but for all the same insurance, mileage, maintanence, why not go suburban and get the extra couple feet of room.
If your going to be towing or plan on owning the vehicle for a long, long, long time, the diesel would be the way to go. If most of your trips are short jaunts around town, or you trade in regularly, the gas engine may be the better power plant to own. Diesels work best when you can run them a bit. Jumping in the truck to dash down to the corner store is not good for them. They also cost more to maintain, like mentioned previously, and those short quick trips increase the necessary maintanence. On the other hand, the gas engine will give up some potential mileage but be quick and easy to maintain. But if all your doing is moving peoplearound town, you may not be giving up that much mileage over the deisel anyway. My neighbor's power stroke isn't particularly stellar around town, but does shine on the highway, and about the time either of my gas mills are in deserate need of a rebuild, his will still be plugging along.