I've had the 7.3s, couple 6.0s, skipped the 6.4s, and now have a 6.7. The first 6.0 I had got bought back by Ford- total disaster of a motor. Had maybe three more 6.0s and the '07 was by far the best, zero issues with it. The new 6.7 was a bit of a gamble, but I felt Ford could not risk a bomb at this point or it would crush them. I have 30k on mine, and absolutely love it. Kept it over my Power Wagon, mainly due to the power and fuel mileage. It is an electronic motor for sure, but lots of the data is geared towards longevity, ie: coolant mixture issue. Translated, check the ph, which was the issue on the previous EGR valves getting corroded and failing. Also, the DEF is an inconvenience, but botom line: 400hp, 800 ft lb torque, mid to upper 20s(mpg) IF below 65mph, 15mpg towing 10k#.
I must note to get the mileage I am, I ordered 3.55s, went to 37" A/T's as the torque can compensate easily. At 65mph I am at around 1200 rpm, and it still pulls the hills without downshifting. The 6 speed is also a big help. Bottom line, in my 40 years of driving, this is the finest most capable truck I have ever had or seen.