It is true that the way we end up driving these is accelerator to the floor,
when you eventually reach desired speed, back off throttle.

I tell people that my car does not accelerate - it accumulates speed.

What you are experiencing is probably normal, even in the very best of circumstances.
But as you noted, when you are up to speed, it runs very well.

The sensation I have driving my diesel 5 cylinders is much like driving a boat.
Open road with cruise or open throttle it is best.

Any gas powered car accelerates differently(better/faster/quicker) than the diesel.
I do not think your car is broken, it is just the quirk of diesels.

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80 300D 340K Owned 30 yrs
83 300SD 440K Owned 9 yrs - Daily Driver 150mi/day
02 Z71 Suburban 117,000
15 Toyota Prius 2600 miles
00 Harley Sportster 24k
09 Yamaha R6
03 Ninja 250