@lewm Yes, what I wrote was ambiguous. I meant, "I agree with Lew (about TT and tonearm being important) AND TT is most important ...".
@pedroeb Absolutely. Which is also why some mechanism of keeping the record flat is so important. Vacuum hold-down is effective but cumbersome, but a reflex clamp is just as good for most records.
@ketchup My tonearm is an air bearing DIY with rock solid shafting and precision adjustments in all directions. The actual fine measurement of azimuth is from a fine scale counter marked in 100 micron increments, but capable of repeating to within 20 microns. Since the beam is 254 mm, resolution is calculated quite accurately by the small angle relation tan ~ sin ~ angle in radians, and 20 microns corresponds to about 30 seconds of arc. Adjustments on this scale are not sufficient to impair horizontality much at all, and so I have azimuth on the fly. Adjustment is secured by a brake.