Inspired by this thread, I finally got 'round to replacing my IVY 2.0 with the IVY-III. It's a dramatic change! The III is much more analogy. Everyone is tapping their feet now, so overall the III is a clear winner in terms of PRaT and overall organic character of the sound. However, I find the sound to be a tad veiled and the HFs lacking in slap and shimmer.
Are there tweaks to the IVY-III discussed anywhere? I found the "In Praise of Legato" thread with loads of tweaks, but folks there describe the Legato as more mellow, so I think I'd better stick with the IVY-III. The only thing I can think to try is to play with the rail decoupling.