Upgrades for Rega P3. Worth it?


Good afternoon, all. Have been considering various upgrades to my Rega P3 and wondering if anyone could share their own experiences with this. In particular, looking for real advice on whether certain upgrades were worthwhile and/or had an observable benefit to sound quality to people who've done them.

I currently have a P3 with an Ortofon 2M Blue cartridge, Clearaudio counterweight, and Pro-ject Tube Box SE II phono stage. Potential upgrades I have considered:
Rega TT PSU power supply,
Groovetracer (or other) subplatter,
Groovetracer (or other) acrylic platter (vs. stock glass),
Phono cartridge replacement

Are any of these really worth doing?
nichomoff
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Have you considered the Rega White Belt? Maybe it was because the old belt was wearing out, but for me the white belt was a major improvement. A few weeks later I installed the Groovetracer reference subplatter and the noice floor dropped.

I have the P3-24 with the power supply and exact cart.