@macg19
Thanks! I tried my Jade on Clearaudio Universal 12" VTA - and that was quickly the end of further Koetsu experiments on the arm. Tracks and plays fine. It's just sonically very flat and dull. Definitely lacking sparkle. Jade is probably the worst Koetsu to match here, for that reason - similar to Coralstone, it's especially warm, even for a Koetsu. If I had to guess, I'd blame the carbon fiber wand more than the mass / compliance match. That Universal arm generally has a bit of a relaxed top end. It matches better to Ortofons, Benzes, and Shelter Harmony.
If I were to try Koetsu again on a Tracer (which looks like a really nice arm in its own right), since it has the carbon fiber wand I'd want samarium cobalt magnets (punchy) and the metal body of Black (I generally like metal bodies on cartridges). The Rosewood and Urushis also use samarium cobalt magnets and could be good, but honestly the Black seems like it could slot in really nicely there. Unfortunately I haven't heard these Koetsu models, but being somewhat familiar with the effect of magnet types and body materials, this would be my best guess!
If you want to scale up, a used Fidelity Research FR64fx in good condition ($1500) is hard to beat for a match to Koetsu. You'd just need an armboard, and I'm not certain if it could fit the Performance / Ovation's small circular armboard. Perhaps worth checking though. I really love these FR arms on my Innovation series tables. Not just for Koetsu, either. On Innovations and Solutions, the FR64fx fits (only just, but it does) on their standard Graham Phantom long / flat armboard. Also have the Graham Phantom II Supreme and it's really good sounding and a dream to setup, but dang I just like those FR arms.