My OFF-ROAD POPUP weighs in at 4200lbs and I use the 2010 F150 super cab to pull it with. Having the rear seat makes it great for addition passengers. All of us are comfortable. The newer truck have more legroom for the rear seat area as the older trucks had. The other HUGH plus is we have the use of the truck bed for carrying our 2KW generator and camping supplies. Of course our OFF-ROAD POPUP setup has the front deck so we can carry some serious supplies on our camping trips.
My F150 truck gets almost the same 18-20MPG whether pulling our trailer or not. We can drive from here in VA to Gatlingburg TN Smoky mtns (460Mi) without having to stop for gas. Of course I usually stop after the tank starts getting below half a tank.
Our big OFF-ROAD POPUP has all the modern appliances etc and we have plenty of room for us. We also can still do the McDonalds drive thru and order from the drive through window hehe...