Not sure how different the newer PFDI 3.5L is but we had a Duratec 3.5L V6 in a MkZ that we drove the bejeezus out of. We put more miles on that car then anything I've ever owned. It had nearly 250,000 on it when we traded it in and except for routine oil & filter, air filter changes, and spark plugs once that engine ran perfectly without a single issue ever. Wife's new car is 2011 MkS with 3.5 Ecoboost, I think we're around 114K on it, and as jackelope mentioned there's night and day difference with regard to power and it has been flawless so far as well. Had a 2017 Explorer with 3.5L Ecoboost for a couple years but we didn't have it very long I think it only had around 20K when we sold it but it too had zero issues.
A good friend of mine had the first year they put 3.5 Ecoboost in the F150's. He had over 280,000 on it when he bought a new one in 2022 and I wouldn't consider him real high on maintenance but other then basic oil & filters changes and maybe spark plugs once he had zero issues with it.
There's good and bad with any brand but I think, some, of the horror stories you hear/read about get shouted out and made into being the norm when they're the exception.