At the time I was shopping, it was the diesels that had a horrible reputation. Lawsuits back and forth between the engine manufacturer and Ford, lawsuits from ambulance companies, friends with blown diesels and very expensive repair bills... Not to mention the standard diesel problems - smell, noise, smoke, price, cost of fuel, cost of maintenance...
The first year or two the V10 had some reliability issues related to the spark plug threading. A non-issue after that.
Back when my truck was made, the V8 was underpowered, especially for climbing hills at 75mph at this elevation. The V10 was dropped from the line only when the new V8 engine was released; the new V8 has more power than my V10.
I've had it about six years now. It's held it's value (according to NADA) very well, and it's had a few standard maintenance items pop up but nothing that I'd consider a design defect. Battery, brakes, starter, oil changes. It's now 11 years old and still looks like new too.