Dave, I had not seen those data from John Ellison. Thanks for the URL. Actually, given the premise that one cannot "hear" tracking angle error; one can only hear tracking distortion, I find it surprising in fact that there is so little difference between the pivoted example and the SL example with 0.5mm overhang error, comparing only the red curves for distortion. At worst, when the stylus is between 80 and 90mm from the center of the LP, the pivoted arm gives about 0.7% tracking distortion vs ~0.2% for the very slightly misaligned linear tracker. At other distances from the center of the LP, the difference in distortion is much less and sometimes in favor of the pivoted arm. I wonder at the audibility of this difference (but I know you say you can hear it). I also wonder how many SL tonearms are running with this much set-up error and worse. I would guess it is not uncommon for there to be an +/-0.5mm error in set-up.