The teeny tiny changes needed to get azimuth right are a reality. I use the cheaper version of Wally's Analog Shop - bought it a few years ago before the price leaped up. Took me several hours of patient patience to move my SME's adjustable headshell just so. We're talking a movement distance of less than or equal to the thickness of a line on a ruler, less than the thickness of a line drawn with a thin-tip ballpoint pen. You cannot breath out while you do this!
The reason I give priority to the Wally instead of my ears is assurance of repeatability from one day to the next, and being able to get the crosstalk lower. Do your best with your ears, then measure with the Wally. My ears got me inside 4dB, Wally got me under 1dB. An expensive cure for audiophilia nervosa but I'm happy to have the device.
Tim
The reason I give priority to the Wally instead of my ears is assurance of repeatability from one day to the next, and being able to get the crosstalk lower. Do your best with your ears, then measure with the Wally. My ears got me inside 4dB, Wally got me under 1dB. An expensive cure for audiophilia nervosa but I'm happy to have the device.
Tim