The 7.3s had their issues, but they are minor compared to those of the 6.0. I've owned four 7.3s and bought my last one a year earlier than I had planned to avoid the new 6.0. I'm glad I did.
The 7.3 was prone to oil leaks, and had a cam positioning sensor that would fail almost regularly. The oil pans rot out prematurely and the solenoid for the glow plugs has a high failure rate. But they rarely experienced total failure as have a number of 6.0s. A friend of mine who has owned Fords for years and always has a fleet of 5 or more in his business has had two of them blow up, one on the way home from the dealer when he picked it up new.
I've been a Ford man when it comes to trucks for as long as I can remember, but my current trucks are most likely the last ones I'll own. I've had nothing but trouble with them and have received little help from the dealers during the warranty period. They are both 7.3s and I've replaced the CPS on both of them plus the oil pans. One currently needs the glow plug solenoid. There have been other engine problems covered by warranty, but I've had many chassis issues too. When I've scheduled them for repairs I've often had to take them in twice for the same repair, it seems I have to argue with the service rep on what is actually the problem. Today's mechanics can't diagnose unless the on board computer tells them there is something wrong.
Nest time around I'm going to be looking for an alternative.
