I just did the same "Trade up". I definitely like the 2008 job 1 over the 2004, but mileage SUCKS. I checked the oasis report to verify that the radiator was replaced and the tee was installed. I would check to make sure that the known common issues have already been addressed, or that it is still under warranty. I bought mine with 75,000 miles, but I will definitely still get the 7/200,000 Ford Diesel Enginecare warranty, as I cannot afford the types of financial surprises the 6.0 brought in repairs. I believe it is a better/stronger motor, but it is still HIGH maintenance.
Much quieter, more powerful, much nicer ride, much thirstier.