I added the Express Machining "Heavyweight" counterweight to my Rega RB900 about 2 years ago (I have since sold the RB900 and replaced it with a Rega RB1000), and I was VERY pleased with the improvement it made. Infact, I wrote a review about the counterweight here on Audiogon, which you should be able to find in the archives.
In short, I strongly urged owners of the Rega tonearms to buy this replacement counterweight, as the improvements it provided were significant.
In short, I strongly urged owners of the Rega tonearms to buy this replacement counterweight, as the improvements it provided were significant.