When I lived in South Africa the TD5 was about a year old. I got to spend a bit of time as a passenger in a TD5 Disco. The owner quite liked it but the old school Rover crowd grumbled about the engine having greater electronic complexity than was needed in Defenders. As with most engines in Rovers, this version had its share of issues. I think the main one was that leaking oil could contaminate a wiring loom, causing electrical problems.
Since there aren't very many of these engines in the States you won't find a lot of information about them on this forum. I suggest you look for a similar forum based out of the UK, where thee TD5 was widely used and is understood in much greater depth. You'll have better luck finding answers to your questions on a site like that. Good luck, and if you get a TD5, please report back on it.