Well, maybe Alvis' & Bristol's could accommodate 'never tall children, even for their age', but if you were used to bespoke, handbuilt cars in your childhood, then I'm sure any car which arrived in your family 'off the line', so to speak would have been ripe for your youthful disdain, even though their shortcomings would have been very apparent to the dispassionate & experienced driver. To people used to less rarefied transport however, the P6 must have come as something of a revelation.
No, the four-pot isn't the smoothest lump in the world & I can identify with the steering being a bit vague, if you're piloting a P5B. The P6 however, even with PAS would seem to me at least, to go anywhere you point it. Perhaps the gentleman was talking about the very earliest cars with the sharkstooth valence being driven at top speed for prolonged periods of time.
I'm inclined to agree with Demetris here. People like to try to impress others with their implied lifetime experience of the upper classes of the automobile, though I come at this having never driven a Jaguar, Alvis or Bristol.
I did learn to drive in a Dolomite, though can't say I was thinking of anything else at the time other than passing my driving test, except to form the impression that the Triumph was a pleasant little car & that I wouldn't mind owning one. I never have, however, being already smitten by the lines of the Rover, which still aesthetically trump the somewhat clumsy silhouette of the PI's given that the Mkl 2000 is a very attractive car.
The Ian Macdonald letter gave me a good few laughs . Hire a teenager whilst he still knows everything ! Unfortunately, this teenager never seems to have grown up. I have owned all the cars he describes, and frankly his letter is nonsense almost from beginning to end . At a rather stiff 70 and still just about 6 feet, I can sit comfortably in any of the four seats of my Rover 2000TC . Also, I cannot agree about the engine, which I have always thought ( since my first one in the late 60s) was about as smooth as you can get - even the BMW of the era, or the Alfa, both of which were regarded as the yardsticks, were not appreciably smoother. What the Rover engine is, however, is vocal at its top end, and I think this sometimes confuses people