I was a truck driver for a while in the US Marines and despite all of the Humvees and other bog trucks I drove and performed maintinance for, no vehicle has ever been as reliable to me as this vehicle. It has never let me down in the few years I've had it and believe you me has it endured many things since then, several wrecks and off-roading, and overall abuse it still runs magnificent. In spite of all of this, it is fast and comfortable. The only thing bad in my opinion is the fuel economy isn't the greatest and it contains only about a 10-12 gallon fuel tank. The stereo it comes with is loud and many other factory or stock items are very nice for such an old vehicle.
Durability and reliability
Fuel economy. Make mirror assemblies less fragile and tailgate cables more durable. Mine rusted through and broke. Lastly suspension, make it able to have a better payload, sacrifice a bit of weight for a better worktruck which many consumers see attractive