Dover
I have a screw gauge that slips under the arm lift.
1/4 turn of the screw equates to 1/1000 of an inch.
I can hear 1/1000 of an inch like night and day.
Apparently, it takes a 4mm change in the VTA to change the SRA by 1 degree on a 9-inch tonearm, even more on a longer arm. If you can hear a change of 1/1000 of an inch in the VTA, that means that you can hear a change of 0.00635 degrees in SRA, even less if you have a longer arm. You surely are jesting, Dover!
The issue I have with adjusting the VTA for every record and writing it down like Doug and Dover do is that you might very well not have the same setting the next time you listen to that same record even without touching the tonearm. Ambient temperatures will affect the VTF, which in turn will affect the SRA. To illustrate with an extreme example, if Dover can hear a change of 0.00635 degrees in the SRA, a change of a fraction of degree in the ambient temperature would result in a change in the sound that he could hear. I suppose you could account for that by ensuring that the VTF is the same, but that's a lot of work every time you put on a new record, in addition to cleaning the stylus, de-staticking the record and removing any residual dust particles, removing and putting the clamp and the periphery ring back on! Unless you have a listening room that is perfectly air conditioned 24/7...