oh, i am the complete opposite Charlie!
My TD100 was a slug in comparison to the JTD, i get 300km per tank extra from the car with the JTD upgrade, which is reason alone to prefer it. The ECU is so much more informative, the engine is quieter, has virtually no knock (a little at startup) the power curve is smooth and is low on torque at below 1800rpms, which protects the big end bearing when low down in the rev range.
The TD100 was smelly, noisy, inefficient, smoked like a 1950s chimney, and was so unrefined, even a john deere felt smug against it. It grunted from low down and surged violently through 1800 to 2800 but did nothing much any higher.
each to their own i suppose.