well the only experience i have is with 2 6.0 power strokes in my excursion and the old Detroit 6.5 in my h1, the power strokes are good so long as you nip their common issues before they cost you a motor. As im sure the rest of you know, the head studs are terrible as are the vvt turbos, had a turbo turn into shrapnel. If your smart about what mods you do they will last. As for the 6.5 diesel, i could not kill that thing. Now i know you said newer diesels. basically any 6.5 after 99 does not have the #8 cylinder failure problem. And i have to say that clatter heap of a motor just kept going and going. Hope that helps.