Be careful, blocks crack near the main bearings, the injector pumps arent to clever and check the conversion quality.
I learnt the above from owning a badly converted one which I had to re do and another that cracked its block which is another well known problem.
I had some experience of driving one of these (in a RR Classic with auto box) which I used for a couple of towing jobs in 2005. As said, it's not really as powerful as you might expect, but there is shed loads of torque available literally from idle speed.
Slower than a TDi in my opinion, but then it was a slush box, but the torque and sound was quite impressive. Managed a ~2T trailer quite well.
Can't comment on reliability, but have also heard that they're not the most reliable of blocks.
A breathed on TD5 will knock spots off it in every possible way though, I know mine would