We ordered our 03 450 just before the cutoff date came. The dealer tried to push us into waiting, but why wait when we knew what we liked. I'm glad we did! This truck has been great. It was rated at 275 (according to the dealer) and has had the simple mods done to it from the beginning. It pulls great and has never given any problem. Just yesterday it brought a 20k pound tractor/gooseneck back to TN from middle KY. I never got passed by any loaded truck coming 300 miles. It pulled the mountains at 65 mph and the lowlands at 75 with ease.
As for the 6.0's having more power, we have been down that road too. I have pulled side by side with our other 6.0's with this 03 7.3. Similar loads with similar driving habits and they couldn't hang with it. Empty, they would smoke it. But, what's a Superduty really built for? Hauling if you ask me.