I've got a 7.3, and I've averaged 10K miles per year since buying it 12 years ago. Other than a tuner, mine is completely stock.
They're very durable and very reliable.
And if you put a 80 hp econo tune on it, it'll be a very quick vehicle. Mine would chirp a tire when new. Now, it'll do burnouts from a dead stoop. I can stomp the throttle at 20 mph, and see two long black streaks in the rear view mirror.
And I went from 18 mpg to a current 20 mpg on the open road. Only problem is keeping rear tires from wearing.