@ valinar
It has been a few years, but one distinct thing I remember is the improvement in tonal and timber accuracy of the piano after replacing the sub-platter and belt.
My memory is not that good to be able to recall the exact type of improvements that resulted in changing the counter weight. I will say, without leading you astray that I believe you will hear finer detail due to greater accuracy in tracking of vertical modulation.
I don't want to solicit a product here, but in addition to the mods we have discussed, one of the most obvious improvements that came about on my turn table source was replacing the Black Cube SE PWR Box fuse with a Synergistic Research Black fuse. I have a PC of there's now powering my CDP. One of these day I plan to swap it out to see/hear what gains are made.
Recently I purchased a Lyra Delose. I set up tangent and overhang alignment using the Rega supplied gauge.
From conversation and reading, I understand vast improvements are heard by using a Mint or Wally Tractor gauge. So the research and pursuit of one of those gauges is in progress.
Rather than discuss off topic here, if you want to talk further on the subject, you are welcome to use the PM message feature of this site to contact me.