Correction to my above post, looks like the signature version of the JMW 9 is a significant upgrade.
Straight from the VPI webpage...
New JMW-9 Signature tonearm The Signature version of the JMW-9 features a stainless steel bearing assembly, fine tracking force adjustment on the counterweight stem, Nordost Valhalla wiring. It has 2.5 grams more effective mass for lighter cartridges of low compliance, a larger more solid design, variable pivot fluid damping, and mechanical anti-skate control.
Straight from the VPI webpage...
New JMW-9 Signature tonearm The Signature version of the JMW-9 features a stainless steel bearing assembly, fine tracking force adjustment on the counterweight stem, Nordost Valhalla wiring. It has 2.5 grams more effective mass for lighter cartridges of low compliance, a larger more solid design, variable pivot fluid damping, and mechanical anti-skate control.