Dear Dgob: There is no doubt that exist a scientific ( physic/mathematic and the like. ) answer for many audio phenomenons but the issue is that till today does not exist and no one already attempt to " build " an audio model that not only has all the audio factors/parameters involved when we are talking to predict for sure audio system or audio item quality performance level but that has all the interactions/relationship between those factors/parameters that have influence in that " live " performance. DT " won't go on theoretical here " because IMHO he has nothing on hand that could give you a prediction about performance sound between cartridge/headshell/tonearm and its several alternatives on weight, compliance, stylus shape, cantilever material, headshell build material, tonearm whole design, internal cable, cartridge pin connectors, cable, phono stage and the like.
The best IMHO that we can do is try different alternatives and over hundred maybe thousands of " observation " method achieve some partial conclusions.
Yes, I agree with you: that scientific " stage " almost always arrive late to the audio party, especially when we are talking of quality performance level on analog because when we are talking of electronic designs the scientific " stage/path " is the first guest to arrive. So depend of waht we are talking about and what we want to know and with what level of consistence and accuracy. I'm with the scientific " road " always that can be use it and always when is " practical/workable ".
Regards and enjoy the music,
R.