Brooks Berdan was a big fan of the Oracle Delphi (he even came up with a mod for it, which Oracle ended up copying), to which he mounted many of the Eminent Technology arm. But when the HW-19 (and then the TNT) was introduced, he switched allegiance to that high mass design for use with the ET, feeling it provided a better platform for the moving mass of the arm's wand.
In addition to Herbies Tall Firm Tenderfeet, the SIMS Navcom Silencers are popular replacements for the HW-19's stock suspension springs.