I personally think PSA make the best Diesels.
But the 1.9 VAG SDI unit is a very tough unit. I have seen one example in a private hire taxi that has done 800K.
I think the older designs with fewer bells and whistles and less to go wrong are the best.
They're also not fussy about what you feed them.
A case of don't fix what ain't broken. I remember the days when you could see the ground below the engine and look at the inside walls of your tyres.
Modern engines don't have enough room to put your fag packet and cup of tea down! Far too much gimmickry for me to be honest.