Overall, I have been pleased with this truck. Pros: carries everything, comfortable. Cons: poor gas mileage, third row seats don't fold flat. The biggest negative comes when you go to get the truck fixed. Ford seems to hide parts in hard-to-find places. Replacing the $50 front heater core requires $600 of labor to remove all the other parts that block it.
Single feature? Comfort. For its size, it's not too unwieldy.
The newer models have folding 3rd row seats, so it looks like they fixed that. I'm looking to replace this vehicle now, but the 2006 Expedition's interior seems much cheaper.