As someone who has made many hundreds of 30 IPS half track masters - mostly for PBS broadcasts - in the late '70s and throughout the '80s, and an even larger number of 15 IPS half track masters from the early '70s through the '80s, it was obvious that the sound of the tape machine (except for the dreaded head bump at 50 hZ on ALL 30 IPS machines) could be changed/adjusted to taste. That's why I cannot remember any two machines from different owners/sources EVER sounding alike.
The notion that analog tape is inherently superior completely sidesteps this issue.
Here is the most relevant part of the article, as seen from a user's viewpoint:
Different machines and headstacks have different frequency responses and low-frequency emphasis curves known as the “head bump,” while different brands and formulations of tape have different characteristics and require different alignment and initial setup. Let us not forget about the (most commonly used) different tape speeds – 15 and 30 inches-per-second or IPS – which bring their own sets of proverbial pajamas to the party.
Various formulations of tape come with their own instructions for ideal alignment and signal levels. But for many record-makers, these aren’t seen as hard rules – rather, nothing more than wide-goalpost guidelines.
Two engineers can be using the same exact tape machine and the same exact kind of tape and wind up with two completely different sounding rigs before a single microphone is hung in the live room.
And what about analog tape’s infamous sonic limitations and irregularities? By their very nature, many of these are also moving targets which will morph the sound of analog recording from day to day, ear to ear.
We’ve got some technical “uglies” inherent to the format – some of which can be heard plain-as-day from the first print and some that take several passes across the heads of the machine to make themselves known.
In addition to your standard noise and tape hiss, you’ve got the phenomena known as wow-and-flutter – a subtle to not-so-subtle variation in speed and pitch due to nonuniform tape motion during recording, playback or both. This is typically related to the design of the machine, wear and tear, and the physical properties of tape itself. And – ah, yes – low-level print-through of signal from one layer of tape to the next.
Oh, and then there's distortion. Incoming and outgoing signal levels, the tape machine’s electronics, the actual tape itself and the adjustment of an inaudible bias signal are all factors. Each one alters how, when and where distortion occurs and whether that distortion is delightfully pleasing or unbearably awful.