I had a HW-19 Mk III and then a TNT Mk II, both with ET-2 linear tracking arms. At the time (early '90s), I thought the TNT was a major improvement, but it's a little hard to remember the specifics.
I since went with a pair of heavily modded idler-drive Lencos by Jean Nantais and am currently using the latest one, dating from 2005 with subsequent modifications and updates. No question in my mind that the Lencos significantly outperform the VPIs, at least of that era.