For me, it seems to depend on what you read, or who you ask.
I read several forums, some with dedicated Sprinter sections, and the majority opinions there seem to refute those negative reviews and articles. Most owners seem happy with them, based on what I see.
They have issues, just like every power train, but there seem to be mitigating circumstances that make service and maintenance a push between the MB 3.0L V6 D and the other options. I know my V10 was a stump puller, but it had a few negatives that made me consider trying something else.
We'll see how things go, I guess. Right or wrong.