Ive had good luck out of the 7.3's and like em but when my current one is ready to be replaced it will probably be a Dodge Mega cab diesel that takes its place.Provided I can find one that has a good bed on it.
My f250 doesn't have enuf susp for my taste in some towing situations.
I had a SW f350 before and the susp was better but load placement on the trailer was more critical since it was just SW.
Current F350 is crewcab and dw so not as much tail waggin the dog as a sw truck.
I know some use waste oil and like it but I never really saw the savings in usin it.By the time you buy/make the stuff to filter/process the oil and the additives,and count your time driving around to every greasy spoon diner in town it just doesn't add up,esp at current prices.