I have never understood the race to derv.
They have no soul and are devoid of passion.
They are purely about economy.
A 4500 RPM redline while sounding like a cement mixer does nothing for me*
* Apologies to all the derv lovers here at OOF. 
On diesels of 20 years I would agree with you, but today's offerings are a lot different.
My brother had a 3 litre XF Twin Turbo that was an absolute animal when the right foot was planted, and hitting the speed limiter (155 mph) was very easily done if you wanted it. Combine that with the ridiculous amount of torque it developed and it was a dangerous car in the wrong hands (even more so with the computer in race mode).
As for hearing it, it was moderately difficult to tell it was a diesel from the outside and impossible to tell from the inside.
Granted it was an expensive car when he bought it (£38K @ 1 year old) so you would expect those sort of refinements, the cheaper end of the market is probably still a different story though.