Why Upgrade the Rega Counterweight?


I recently acquired a new Rega P3-24 with the Elys cartridge. Out of curiosity, I've been looking at the tweaks and upgrades for this unit. Have any of you actually replaced the stock counterweight? What differences did it make?

What about the white Drive belt that's advertised, does this really make a difference? Is the stock belt so poorly engineered that it can be improved with an upgrade? Why wasn't it installed as original equipment by Rega?

I'm really enjoying this table as it is through my Sansui AU20000. I also have the TT PSU which is essential for this table IMHO.

If there were effective tweaks that I could apply to this table to further improve it, I would be interested.
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I changed to the Origin Live endstub/counterweight. Seemed to clarify everything. That said, I would not recommend investing in incremental upgrades to Rega arms. It is money down the drain, at resale time. Better to save up and get a better arm.
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I heard a significant improvement in the bass when I replaced the stock counterweight of an RB300 with a Michell Tecnoweight. Here's a good review that explains the design: Vinyl Engine: Michell TecnoWeight
Thanks to all of you for the great replies. The physics of the Michell design make a lot of sense. You also addressed my primary question of whether you could hear a difference. It's a no brainer, I have a Tecnoweight on order. I especially like the micrometer like adjustment for VTF.

Sometime next year I'll be replacing my Rega Elys. I now see that the Michell design allows for a lot of different cartridge choices that the stock setup limits.

It was reassuring to see that no-one (so far?) furiously defended the white drive belt upgrade. I'd hoped it would only provide a minor contribution to the sound at best, otherwise shame on Rega for initially supplying something so basic (and essential) to their table with an inferior quality. I might consider one when the time comes to replace the original belt but to outright change it as an improvement rubs me the wrong way.

I have other Rega upgrade questions but I'll start a new thread to keep the topics distinct. Sincere thank you's again.