With my ZYX modified by Soundsmith, I have noticed significant difference in sound quality based upon record thickness. I have had it set perfect for my Sheffield Lab records, which are not that heavy. When I played 200 gram records, I could really hear the difference. So I started adjusting my VTAF (VTA on the Fly). When I put on a record, I start playing and then if the sound does not provide the right mix bass to highs and resolution, I spin the dial on the VTAF. I am finding that it only takes a little adjustment to make a Huge difference.
As I advance with my vinyl mania, I am finding the sound quality to be amazing, and so much better than my CD's.
Reportedly VTA changes are are particularly noticeable when you use a Line Contact Stylus.